java.lang.Object

org.openprovenance.apache.commons.lang.StringUtils

public class StringUtils extends Object

Operations on String that are null safe.

IsEmpty/IsBlank - checks if a String contains text
Trim/Strip - removes leading and trailing whitespace
Equals - compares two strings null-safe
startsWith - check if a String starts with a prefix null-safe
endsWith - check if a String ends with a suffix null-safe
IndexOf/LastIndexOf/Contains - null-safe index-of checks
IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut - index-of any of a set of Strings
ContainsOnly/ContainsNone/ContainsAny - does String contains only/none/any of these characters
Substring/Left/Right/Mid - null-safe substring extractions
SubstringBefore/SubstringAfter/SubstringBetween - substring extraction relative to other strings
Split/Join - splits a String into an array of substrings and vice versa
Remove/Delete - removes part of a String
Replace/Overlay - Searches a String and replaces one String with another
Chomp/Chop - removes the last part of a String
LeftPad/RightPad/Center/Repeat - pads a String
UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize - changes the case of a String
CountMatches - counts the number of occurrences of one String in another
IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable - checks the characters in a String
DefaultString - protects against a null input String
Reverse/ReverseDelimited - reverses a String
Abbreviate - abbreviates a string using ellipsis
Difference - compares Strings and reports on their differences
LevensteinDistance - the number of changes needed to change one String into another

The StringUtils class defines certain words related to String handling.

null - null
empty - a zero-length string ("")
space - the space character (' ', char 32)
whitespace - the characters defined by Character.isWhitespace(char)
trim - the characters <= 32 as in String.trim()

StringUtils handles null input Strings quietly. That is to say that a null input will return null. Where a boolean or int is being returned details vary by method.

A side effect of the null handling is that a NullPointerException should be considered a bug in StringUtils (except for deprecated methods).

Methods in this class give sample code to explain their operation. The symbol * is used to indicate any input including null.

#ThreadSafe#

Since:

1.0

Version:

$Id: StringUtils.java 1058365 2011-01-13 00:04:49Z niallp $

Author:

Apache Software Foundation, Apache Jakarta Turbine, Jon S. Stevens, Daniel L. Rall, Greg Coladonato, Ed Korthof, Rand McNeely, Fredrik Westermarck, Holger Krauth, Alexander Day Chaffee, Henning P. Schmiedehausen, Arun Mammen Thomas, Gary Gregory, Phil Steitz, Al Chou, Michael Davey, Reuben Sivan, Chris Hyzer, Scott Johnson

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

static final String

EMPTY

The empty String "".

static final int

INDEX_NOT_FOUND

Represents a failed index search.
Constructor Summary

Constructors

Constructor

Description

StringUtils()

StringUtils instances should NOT be constructed in standard programming.
Method Summary

Modifier and Type

Method

Description

static String

abbreviate(String str, int maxWidth)

Abbreviates a String using ellipses.

static String

abbreviate(String str, int offset, int maxWidth)

Abbreviates a String using ellipses.

static String

abbreviateMiddle(String str, String middle, int length)

Abbreviates a String to the length passed, replacing the middle characters with the supplied replacement String.

static String

capitalise(String str)

Deprecated.
Use the standardly named capitalize(String).

static String

capitaliseAllWords(String str)

Deprecated.
Use the relocated WordUtils.capitalize(String).

static String

capitalize(String str)

Capitalizes a String changing the first letter to title case as per Character.toTitleCase(char).

static String

center(String str, int size)

Centers a String in a larger String of size size using the space character (' ').

static String

center(String str, int size, char padChar)

Centers a String in a larger String of size size.

static String

center(String str, int size, String padStr)

Centers a String in a larger String of size size.

static String

chomp(String str)

Removes one newline from end of a String if it's there, otherwise leave it alone.

static String

chomp(String str, String separator)

Removes separator from the end of str if it's there, otherwise leave it alone.

static String

chompLast(String str)

Deprecated.
Use chomp(String) instead.

static String

chompLast(String str, String sep)

Deprecated.
Use chomp(String,String) instead.

static String

chop(String str)

Remove the last character from a String.

static String

chopNewline(String str)

Deprecated.
Use chomp(String) instead.

static String

clean(String str)

Deprecated.
Use the clearer named trimToEmpty(String).

static String

concatenate(Object[] array)

Deprecated.
Use the better named join(Object[]) instead.

static boolean

contains(String str, char searchChar)

Checks if String contains a search character, handling null.

static boolean

contains(String str, String searchStr)

Checks if String contains a search String, handling null.

static boolean

containsAny(String str, char[] searchChars)

Checks if the String contains any character in the given set of characters.

static boolean

containsAny(String str, String searchChars)

Checks if the String contains any character in the given set of characters.

static boolean

containsIgnoreCase(String str, String searchStr)

Checks if String contains a search String irrespective of case, handling null.

static boolean

containsNone(String str, char[] searchChars)

Checks that the String does not contain certain characters.

static boolean

containsNone(String str, String invalidChars)

Checks that the String does not contain certain characters.

static boolean

containsOnly(String str, char[] valid)

Checks if the String contains only certain characters.

static boolean

containsOnly(String str, String validChars)

Checks if the String contains only certain characters.

static int

countMatches(String str, String sub)

Counts how many times the substring appears in the larger String.

static String

defaultIfBlank(String str, String defaultStr)

Returns either the passed in String, or if the String is whitespace, empty ("") or null, the value of defaultStr.

static String

defaultIfEmpty(String str, String defaultStr)

Returns either the passed in String, or if the String is empty or null, the value of defaultStr.

static String

defaultString(String str)

Returns either the passed in String, or if the String is null, an empty String ("").

static String

defaultString(String str, String defaultStr)

Returns either the passed in String, or if the String is null, the value of defaultStr.

static String

deleteSpaces(String str)

Deprecated.
Use the better localized deleteWhitespace(String).

static String

deleteWhitespace(String str)

Deletes all whitespaces from a String as defined by Character.isWhitespace(char).

static String

difference(String str1, String str2)

Compares two Strings, and returns the portion where they differ.

static boolean

endsWith(String str, String suffix)

Check if a String ends with a specified suffix.

static boolean

endsWithAny(String string, String[] searchStrings)

Check if a String ends with any of an array of specified strings.

static boolean

endsWithIgnoreCase(String str, String suffix)

Case insensitive check if a String ends with a specified suffix.

static boolean

equals(String str1, String str2)

Compares two Strings, returning true if they are equal.

static boolean

equalsIgnoreCase(String str1, String str2)

Compares two Strings, returning true if they are equal ignoring the case.

static String

escape(String str)

Deprecated.
Use StringEscapeUtils.escapeJava(String) This method will be removed in Commons Lang 3.0

static String

getChomp(String str, String sep)

Deprecated.
Use substringAfterLast(String, String) instead (although this doesn't include the separator) Method will be removed in Commons Lang 3.0.

static String

getCommonPrefix(String[] strs)

Compares all Strings in an array and returns the initial sequence of characters that is common to all of them.

static int

getLevenshteinDistance(String s, String t)

Find the Levenshtein distance between two Strings.

static String

getNestedString(String str, String tag)

Deprecated.
Use the better named substringBetween(String, String).

static String

getNestedString(String str, String open, String close)

Deprecated.
Use the better named substringBetween(String, String, String).

static String

getPrechomp(String str, String sep)

Deprecated.
Use substringBefore(String,String) instead (although this doesn't include the separator).

static int

indexOf(String str, char searchChar)

Finds the first index within a String, handling null.

static int

indexOf(String str, char searchChar, int startPos)

Finds the first index within a String from a start position, handling null.

static int

indexOf(String str, String searchStr)

Finds the first index within a String, handling null.

static int

indexOf(String str, String searchStr, int startPos)

Finds the first index within a String, handling null.

static int

indexOfAny(String str, char[] searchChars)

Search a String to find the first index of any character in the given set of characters.

static int

indexOfAny(String str, String searchChars)

Search a String to find the first index of any character in the given set of characters.

static int

indexOfAny(String str, String[] searchStrs)

Find the first index of any of a set of potential substrings.

static int

indexOfAnyBut(String str, char[] searchChars)

Search a String to find the first index of any character not in the given set of characters.

static int

indexOfAnyBut(String str, String searchChars)

Search a String to find the first index of any character not in the given set of characters.

static int

indexOfDifference(String[] strs)

Compares all Strings in an array and returns the index at which the Strings begin to differ.

static int

indexOfDifference(String str1, String str2)

Compares two Strings, and returns the index at which the Strings begin to differ.

static int

indexOfIgnoreCase(String str, String searchStr)

Case in-sensitive find of the first index within a String.

static int

indexOfIgnoreCase(String str, String searchStr, int startPos)

Case in-sensitive find of the first index within a String from the specified position.

static boolean

isAllLowerCase(String str)

Checks if the String contains only lowercase characters.

static boolean

isAllUpperCase(String str)

Checks if the String contains only uppercase characters.

static boolean

isAlpha(String str)

Checks if the String contains only unicode letters.

static boolean

isAlphanumeric(String str)

Checks if the String contains only unicode letters or digits.

static boolean

isAlphanumericSpace(String str)

Checks if the String contains only unicode letters, digits or space (' ').

static boolean

isAlphaSpace(String str)

Checks if the String contains only unicode letters and space (' ').

static boolean

isAsciiPrintable(String str)

Checks if the string contains only ASCII printable characters.

static boolean

isBlank(String str)

Checks if a String is whitespace, empty ("") or null.

static boolean

isEmpty(String str)

Checks if a String is empty ("") or null.

static boolean

isNotBlank(String str)

Checks if a String is not empty (""), not null and not whitespace only.

static boolean

isNotEmpty(String str)

Checks if a String is not empty ("") and not null.

static boolean

isNumeric(String str)

Checks if the String contains only unicode digits.

static boolean

isNumericSpace(String str)

Checks if the String contains only unicode digits or space (' ').

static boolean

isWhitespace(String str)

Checks if the String contains only whitespace.

static String

join(Object[] array)

Joins the elements of the provided array into a single String containing the provided list of elements.

static String

join(Object[] array, char separator)

Joins the elements of the provided array into a single String containing the provided list of elements.

static String

join(Object[] array, char separator, int startIndex, int endIndex)

Joins the elements of the provided array into a single String containing the provided list of elements.

static String

join(Object[] array, String separator)

Joins the elements of the provided array into a single String containing the provided list of elements.

static String

join(Object[] array, String separator, int startIndex, int endIndex)

Joins the elements of the provided array into a single String containing the provided list of elements.

static String

join(Collection collection, char separator)

Joins the elements of the provided Collection into a single String containing the provided elements.

static String

join(Collection collection, String separator)

Joins the elements of the provided Collection into a single String containing the provided elements.

static String

join(Iterator iterator, char separator)

Joins the elements of the provided Iterator into a single String containing the provided elements.

static String

join(Iterator iterator, String separator)

Joins the elements of the provided Iterator into a single String containing the provided elements.

static int

lastIndexOf(String str, char searchChar)

Finds the last index within a String, handling null.

static int

lastIndexOf(String str, char searchChar, int startPos)

Finds the last index within a String from a start position, handling null.

static int

lastIndexOf(String str, String searchStr)

Finds the last index within a String, handling null.

static int

lastIndexOf(String str, String searchStr, int startPos)

Finds the first index within a String, handling null.

static int

lastIndexOfAny(String str, String[] searchStrs)

Find the latest index of any of a set of potential substrings.

static int

lastIndexOfIgnoreCase(String str, String searchStr)

Case in-sensitive find of the last index within a String.

static int

lastIndexOfIgnoreCase(String str, String searchStr, int startPos)

Case in-sensitive find of the last index within a String from the specified position.

static int

lastOrdinalIndexOf(String str, String searchStr, int ordinal)

Finds the n-th last index within a String, handling null.

static String

left(String str, int len)

Gets the leftmost len characters of a String.

static String

leftPad(String str, int size)

Left pad a String with spaces (' ').

static String

leftPad(String str, int size, char padChar)

Left pad a String with a specified character.

static String

leftPad(String str, int size, String padStr)

Left pad a String with a specified String.

static int

length(String str)

Gets a String's length or 0 if the String is null.

static String

lowerCase(String str)

Converts a String to lower case as per String.toLowerCase().

static String

lowerCase(String str, Locale locale)

Converts a String to lower case as per String.toLowerCase(Locale).

static String

mid(String str, int pos, int len)

Gets len characters from the middle of a String.

static String

normalizeSpace(String str)

Similar to http://www.w3.org/TR/xpath/#function-normalize -space

static int

ordinalIndexOf(String str, String searchStr, int ordinal)

Finds the n-th index within a String, handling null.

static String

overlay(String str, String overlay, int start, int end)

Overlays part of a String with another String.

static String

overlayString(String text, String overlay, int start, int end)

Deprecated.
Use better named overlay(String, String, int, int) instead.

static String

prechomp(String str, String sep)

Deprecated.
Use substringAfter(String,String) instead.

static String

remove(String str, char remove)

Removes all occurrences of a character from within the source string.

static String

remove(String str, String remove)

Removes all occurrences of a substring from within the source string.

static String

removeEnd(String str, String remove)

Removes a substring only if it is at the end of a source string, otherwise returns the source string.

static String

removeEndIgnoreCase(String str, String remove)

Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.

static String

removeStart(String str, String remove)

Removes a substring only if it is at the begining of a source string, otherwise returns the source string.

static String

removeStartIgnoreCase(String str, String remove)

Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.

static String

repeat(String str, int repeat)

Repeat a String repeat times to form a new String.

static String

repeat(String str, String separator, int repeat)

Repeat a String repeat times to form a new String, with a String separator injected each time.

static String

replace(String text, String searchString, String replacement)

Replaces all occurrences of a String within another String.

static String

replace(String text, String searchString, String replacement, int max)

Replaces a String with another String inside a larger String, for the first max values of the search String.

static String

replaceChars(String str, char searchChar, char replaceChar)

Replaces all occurrences of a character in a String with another.

static String

replaceChars(String str, String searchChars, String replaceChars)

Replaces multiple characters in a String in one go.

static String

replaceEach(String text, String[] searchList, String[] replacementList)

Replaces all occurrences of Strings within another String.

static String

replaceEachRepeatedly(String text, String[] searchList, String[] replacementList)

Replaces all occurrences of Strings within another String.

static String

replaceOnce(String text, String searchString, String replacement)

Replaces a String with another String inside a larger String, once.

static String

reverse(String str)

Reverses a String as per StrBuilder.reverse().

static String

reverseDelimited(String str, char separatorChar)

Reverses a String that is delimited by a specific character.

static String

reverseDelimitedString(String str, String separatorChars)

Deprecated.
Use reverseDelimited(String, char) instead.

static String

right(String str, int len)

Gets the rightmost len characters of a String.

static String

rightPad(String str, int size)

Right pad a String with spaces (' ').

static String

rightPad(String str, int size, char padChar)

Right pad a String with a specified character.

static String

rightPad(String str, int size, String padStr)

Right pad a String with a specified String.

static String[]

split(String str)

Splits the provided text into an array, using whitespace as the separator.

static String[]

split(String str, char separatorChar)

Splits the provided text into an array, separator specified.

static String[]

split(String str, String separatorChars)

Splits the provided text into an array, separators specified.

static String[]

split(String str, String separatorChars, int max)

Splits the provided text into an array with a maximum length, separators specified.

static String[]

splitByCharacterType(String str)

Splits a String by Character type as returned by java.lang.Character.getType(char).

static String[]

splitByCharacterTypeCamelCase(String str)

Splits a String by Character type as returned by java.lang.Character.getType(char).

static String[]

splitByWholeSeparator(String str, String separator)

Splits the provided text into an array, separator string specified.

static String[]

splitByWholeSeparator(String str, String separator, int max)

Splits the provided text into an array, separator string specified.

static String[]

splitByWholeSeparatorPreserveAllTokens(String str, String separator)

Splits the provided text into an array, separator string specified.

static String[]

splitByWholeSeparatorPreserveAllTokens(String str, String separator, int max)

Splits the provided text into an array, separator string specified.

static String[]

splitPreserveAllTokens(String str)

Splits the provided text into an array, using whitespace as the separator, preserving all tokens, including empty tokens created by adjacent separators.

static String[]

splitPreserveAllTokens(String str, char separatorChar)

Splits the provided text into an array, separator specified, preserving all tokens, including empty tokens created by adjacent separators.

static String[]

splitPreserveAllTokens(String str, String separatorChars)

Splits the provided text into an array, separators specified, preserving all tokens, including empty tokens created by adjacent separators.

static String[]

splitPreserveAllTokens(String str, String separatorChars, int max)

Splits the provided text into an array with a maximum length, separators specified, preserving all tokens, including empty tokens created by adjacent separators.

static boolean

startsWith(String str, String prefix)

Check if a String starts with a specified prefix.

static boolean

startsWithAny(String string, String[] searchStrings)

Check if a String starts with any of an array of specified strings.

static boolean

startsWithIgnoreCase(String str, String prefix)

Case insensitive check if a String starts with a specified prefix.

static String

strip(String str)

Strips whitespace from the start and end of a String.

static String

strip(String str, String stripChars)

Strips any of a set of characters from the start and end of a String.

static String[]

stripAll(String[] strs)

Strips whitespace from the start and end of every String in an array.

static String[]

stripAll(String[] strs, String stripChars)

Strips any of a set of characters from the start and end of every String in an array.

static String

stripEnd(String str, String stripChars)

Strips any of a set of characters from the end of a String.

static String

stripStart(String str, String stripChars)

Strips any of a set of characters from the start of a String.

static String

stripToEmpty(String str)

Strips whitespace from the start and end of a String returning an empty String if null input.

static String

stripToNull(String str)

Strips whitespace from the start and end of a String returning null if the String is empty ("") after the strip.

static String

substring(String str, int start)

Gets a substring from the specified String avoiding exceptions.

static String

substring(String str, int start, int end)

Gets a substring from the specified String avoiding exceptions.

static String

substringAfter(String str, String separator)

Gets the substring after the first occurrence of a separator.

static String

substringAfterLast(String str, String separator)

Gets the substring after the last occurrence of a separator.

static String

substringBefore(String str, String separator)

Gets the substring before the first occurrence of a separator.

static String

substringBeforeLast(String str, String separator)

Gets the substring before the last occurrence of a separator.

static String

substringBetween(String str, String tag)

Gets the String that is nested in between two instances of the same String.

static String

substringBetween(String str, String open, String close)

Gets the String that is nested in between two Strings.

static String[]

substringsBetween(String str, String open, String close)

Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.

static String

swapCase(String str)

Swaps the case of a String changing upper and title case to lower case, and lower case to upper case.

static String

trim(String str)

Removes control characters (char <= 32) from both ends of this String, handling null by returning null.

static String

trimToEmpty(String str)

Removes control characters (char <= 32) from both ends of this String returning an empty String ("") if the String is empty ("") after the trim or if it is null.

static String

trimToNull(String str)

Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.

static String

uncapitalise(String str)

Deprecated.
Use the standardly named uncapitalize(String).

static String

uncapitalize(String str)

Uncapitalizes a String changing the first letter to title case as per Character.toLowerCase(char).

static String

upperCase(String str)

Converts a String to upper case as per String.toUpperCase().

static String

upperCase(String str, Locale locale)

Converts a String to upper case as per String.toUpperCase(Locale).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- EMPTY
  public static final String EMPTY
  
  The empty String "".
  
  Since:
  
  2.0
  
  See Also:
  
  Constant Field Values
- INDEX_NOT_FOUND
  public static final int INDEX_NOT_FOUND
  
  Represents a failed index search.
  
  Since:
  
  2.1
  
  See Also:
  
  Constant Field Values
Constructor Details
- StringUtils
  
  public StringUtils()
  
  StringUtils instances should NOT be constructed in standard programming. Instead, the class should be used as StringUtils.trim(" foo ");.
  
  This constructor is public to permit tools that require a JavaBean instance to operate.
Method Details
- isEmpty
  public static boolean isEmpty(String str)
  
  Checks if a String is empty ("") or null.
  
  StringUtils.isEmpty(null) = true StringUtils.isEmpty("") = true StringUtils.isEmpty(" ") = false StringUtils.isEmpty("bob") = false StringUtils.isEmpty(" bob ") = false
  
  NOTE: This method changed in Lang version 2.0. It no longer trims the String. That functionality is available in isBlank().
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if the String is empty or null
- isNotEmpty
  public static boolean isNotEmpty(String str)
  
  Checks if a String is not empty ("") and not null.
  
  StringUtils.isNotEmpty(null) = false StringUtils.isNotEmpty("") = false StringUtils.isNotEmpty(" ") = true StringUtils.isNotEmpty("bob") = true StringUtils.isNotEmpty(" bob ") = true
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if the String is not empty and not null
- isBlank
  public static boolean isBlank(String str)
  
  Checks if a String is whitespace, empty ("") or null.
  
  StringUtils.isBlank(null) = true StringUtils.isBlank("") = true StringUtils.isBlank(" ") = true StringUtils.isBlank("bob") = false StringUtils.isBlank(" bob ") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if the String is null, empty or whitespace
  
  Since:
  
  2.0
- isNotBlank
  public static boolean isNotBlank(String str)
  
  Checks if a String is not empty (""), not null and not whitespace only.
  
  StringUtils.isNotBlank(null) = false StringUtils.isNotBlank("") = false StringUtils.isNotBlank(" ") = false StringUtils.isNotBlank("bob") = true StringUtils.isNotBlank(" bob ") = true
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if the String is not empty and not null and not whitespace
  
  Since:
  
  2.0
- clean
  public static String clean(String str)
  
  Deprecated.
  Use the clearer named trimToEmpty(String). Method will be removed in Commons Lang 3.0.
  
  Removes control characters (char <= 32) from both ends of this String, handling null by returning an empty String ("").
  
  StringUtils.clean(null) = "" StringUtils.clean("") = "" StringUtils.clean("abc") = "abc" StringUtils.clean(" abc ") = "abc" StringUtils.clean(" ") = ""
  
  Parameters:
  
  str - the String to clean, may be null
  
  Returns:
  
  the trimmed text, never null
  
  See Also:
  
  String.trim()
- trim
  public static String trim(String str)
  
  Removes control characters (char <= 32) from both ends of this String, handling null by returning null.
  
  The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use strip(String).
  
  To trim your choice of characters, use the strip(String, String) methods.
  
  StringUtils.trim(null) = null StringUtils.trim("") = "" StringUtils.trim(" ") = "" StringUtils.trim("abc") = "abc" StringUtils.trim(" abc ") = "abc"
  
  Parameters:
  
  str - the String to be trimmed, may be null
  
  Returns:
  
  the trimmed string, null if null String input
- trimToNull
  public static String trimToNull(String str)
  
  Removes control characters (char <= 32) from both ends of this String returning null if the String is empty ("") after the trim or if it is null.
  The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use stripToNull(String).
  
  StringUtils.trimToNull(null) = null StringUtils.trimToNull("") = null StringUtils.trimToNull(" ") = null StringUtils.trimToNull("abc") = "abc" StringUtils.trimToNull(" abc ") = "abc"
  
  Parameters:
  
  str - the String to be trimmed, may be null
  
  Returns:
  
  the trimmed String, null if only chars <= 32, empty or null String input
  
  Since:
  
  2.0
- trimToEmpty
  public static String trimToEmpty(String str)
  
  Removes control characters (char <= 32) from both ends of this String returning an empty String ("") if the String is empty ("") after the trim or if it is null.
  The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use stripToEmpty(String).
  
  StringUtils.trimToEmpty(null) = "" StringUtils.trimToEmpty("") = "" StringUtils.trimToEmpty(" ") = "" StringUtils.trimToEmpty("abc") = "abc" StringUtils.trimToEmpty(" abc ") = "abc"
  
  Parameters:
  
  str - the String to be trimmed, may be null
  
  Returns:
  
  the trimmed String, or an empty String if null input
  
  Since:
  
  2.0
- strip
  public static String strip(String str)
  
  Strips whitespace from the start and end of a String.
  
  This is similar to trim(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char).
  
  A null input String returns null.
  
  StringUtils.strip(null) = null StringUtils.strip("") = "" StringUtils.strip(" ") = "" StringUtils.strip("abc") = "abc" StringUtils.strip(" abc") = "abc" StringUtils.strip("abc ") = "abc" StringUtils.strip(" abc ") = "abc" StringUtils.strip(" ab c ") = "ab c"
  
  Parameters:
  
  str - the String to remove whitespace from, may be null
  
  Returns:
  
  the stripped String, null if null String input
- stripToNull
  public static String stripToNull(String str)
  
  Strips whitespace from the start and end of a String returning null if the String is empty ("") after the strip.
  
  This is similar to trimToNull(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char).
  
  StringUtils.stripToNull(null) = null StringUtils.stripToNull("") = null StringUtils.stripToNull(" ") = null StringUtils.stripToNull("abc") = "abc" StringUtils.stripToNull(" abc") = "abc" StringUtils.stripToNull("abc ") = "abc" StringUtils.stripToNull(" abc ") = "abc" StringUtils.stripToNull(" ab c ") = "ab c"
  
  Parameters:
  
  str - the String to be stripped, may be null
  
  Returns:
  
  the stripped String, null if whitespace, empty or null String input
  
  Since:
  
  2.0
- stripToEmpty
  public static String stripToEmpty(String str)
  
  Strips whitespace from the start and end of a String returning an empty String if null input.
  
  This is similar to trimToEmpty(String) but removes whitespace. Whitespace is defined by Character.isWhitespace(char).
  
  StringUtils.stripToEmpty(null) = "" StringUtils.stripToEmpty("") = "" StringUtils.stripToEmpty(" ") = "" StringUtils.stripToEmpty("abc") = "abc" StringUtils.stripToEmpty(" abc") = "abc" StringUtils.stripToEmpty("abc ") = "abc" StringUtils.stripToEmpty(" abc ") = "abc" StringUtils.stripToEmpty(" ab c ") = "ab c"
  
  Parameters:
  
  str - the String to be stripped, may be null
  
  Returns:
  
  the trimmed String, or an empty String if null input
  
  Since:
  
  2.0
- strip
  public static String strip(String str, String stripChars)
  
  Strips any of a set of characters from the start and end of a String. This is similar to String.trim() but allows the characters to be stripped to be controlled.
  
  A null input String returns null. An empty string ("") input returns the empty string.
  
  If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char). Alternatively use strip(String).
  
  StringUtils.strip(null, *) = null StringUtils.strip("", *) = "" StringUtils.strip("abc", null) = "abc" StringUtils.strip(" abc", null) = "abc" StringUtils.strip("abc ", null) = "abc" StringUtils.strip(" abc ", null) = "abc" StringUtils.strip(" abcyx", "xyz") = " abc"
  
  Parameters:
  
  str - the String to remove characters from, may be null
  
  stripChars - the characters to remove, null treated as whitespace
  
  Returns:
  
  the stripped String, null if null String input
- stripStart
  public static String stripStart(String str, String stripChars)
  
  Strips any of a set of characters from the start of a String.
  
  A null input String returns null. An empty string ("") input returns the empty string.
  
  If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char).
  
  StringUtils.stripStart(null, *) = null StringUtils.stripStart("", *) = "" StringUtils.stripStart("abc", "") = "abc" StringUtils.stripStart("abc", null) = "abc" StringUtils.stripStart(" abc", null) = "abc" StringUtils.stripStart("abc ", null) = "abc " StringUtils.stripStart(" abc ", null) = "abc " StringUtils.stripStart("yxabc ", "xyz") = "abc "
  
  Parameters:
  
  str - the String to remove characters from, may be null
  
  stripChars - the characters to remove, null treated as whitespace
  
  Returns:
  
  the stripped String, null if null String input
- stripEnd
  public static String stripEnd(String str, String stripChars)
  
  Strips any of a set of characters from the end of a String.
  
  A null input String returns null. An empty string ("") input returns the empty string.
  
  If the stripChars String is null, whitespace is stripped as defined by Character.isWhitespace(char).
  
  StringUtils.stripEnd(null, *) = null StringUtils.stripEnd("", *) = "" StringUtils.stripEnd("abc", "") = "abc" StringUtils.stripEnd("abc", null) = "abc" StringUtils.stripEnd(" abc", null) = " abc" StringUtils.stripEnd("abc ", null) = "abc" StringUtils.stripEnd(" abc ", null) = " abc" StringUtils.stripEnd(" abcyx", "xyz") = " abc" StringUtils.stripEnd("120.00", ".0") = "12"
  
  Parameters:
  
  str - the String to remove characters from, may be null
  
  stripChars - the set of characters to remove, null treated as whitespace
  
  Returns:
  
  the stripped String, null if null String input
- stripAll
  public static String[] stripAll(String[] strs)
  
  Strips whitespace from the start and end of every String in an array. Whitespace is defined by Character.isWhitespace(char).
  
  A new array is returned each time, except for length zero. A null array will return null. An empty array will return itself. A null array entry will be ignored.
  
  StringUtils.stripAll(null) = null StringUtils.stripAll([]) = [] StringUtils.stripAll(["abc", " abc"]) = ["abc", "abc"] StringUtils.stripAll(["abc ", null]) = ["abc", null]
  
  Parameters:
  
  strs - the array to remove whitespace from, may be null
  
  Returns:
  
  the stripped Strings, null if null array input
- stripAll
  public static String[] stripAll(String[] strs, String stripChars)
  
  Strips any of a set of characters from the start and end of every String in an array.
  Whitespace is defined by {link Character#isWhitespace(char)}.
  A new array is returned each time, except for length zero. A null array will return null. An empty array will return itself. A null array entry will be ignored. A null stripChars will strip whitespace as defined by Character.isWhitespace(char).
  
  StringUtils.stripAll(null, *) = null StringUtils.stripAll([], *) = [] StringUtils.stripAll(["abc", " abc"], null) = ["abc", "abc"] StringUtils.stripAll(["abc ", null], null) = ["abc", null] StringUtils.stripAll(["abc ", null], "yz") = ["abc ", null] StringUtils.stripAll(["yabcz", null], "yz") = ["abc", null]
  
  Parameters:
  
  strs - the array to remove characters from, may be null
  
  stripChars - the characters to remove, null treated as whitespace
  
  Returns:
  
  the stripped Strings, null if null array input
- equals
  public static boolean equals(String str1, String str2)
  
  Compares two Strings, returning true if they are equal.
  
  nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.
  
  StringUtils.equals(null, null) = true StringUtils.equals(null, "abc") = false StringUtils.equals("abc", null) = false StringUtils.equals("abc", "abc") = true StringUtils.equals("abc", "ABC") = false
  
  Parameters:
  
  str1 - the first String, may be null
  
  str2 - the second String, may be null
  
  Returns:
  
  true if the Strings are equal, case sensitive, or both null
  
  See Also:
  
  String.equals(Object)
- equalsIgnoreCase
  public static boolean equalsIgnoreCase(String str1, String str2)
  
  Compares two Strings, returning true if they are equal ignoring the case.
  
  nulls are handled without exceptions. Two null references are considered equal. Comparison is case insensitive.
  
  StringUtils.equalsIgnoreCase(null, null) = true StringUtils.equalsIgnoreCase(null, "abc") = false StringUtils.equalsIgnoreCase("abc", null) = false StringUtils.equalsIgnoreCase("abc", "abc") = true StringUtils.equalsIgnoreCase("abc", "ABC") = true
  
  Parameters:
  
  str1 - the first String, may be null
  
  str2 - the second String, may be null
  
  Returns:
  
  true if the Strings are equal, case insensitive, or both null
  
  See Also:
  
  String.equalsIgnoreCase(String)
- indexOf
  public static int indexOf(String str, char searchChar)
  
  Finds the first index within a String, handling null. This method uses String.indexOf(int).
  
  A null or empty ("") String will return INDEX_NOT_FOUND (-1).
  
  StringUtils.indexOf(null, *) = -1 StringUtils.indexOf("", *) = -1 StringUtils.indexOf("aabaabaa", 'a') = 0 StringUtils.indexOf("aabaabaa", 'b') = 2
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChar - the character to find
  
  Returns:
  
  the first index of the search character, -1 if no match or null string input
  
  Since:
  
  2.0
- indexOf
  public static int indexOf(String str, char searchChar, int startPos)
  
  Finds the first index within a String from a start position, handling null. This method uses String.indexOf(int, int).
  
  A null or empty ("") String will return (INDEX_NOT_FOUND) -1. A negative start position is treated as zero. A start position greater than the string length returns -1.
  
  StringUtils.indexOf(null, *, *) = -1 StringUtils.indexOf("", *, *) = -1 StringUtils.indexOf("aabaabaa", 'b', 0) = 2 StringUtils.indexOf("aabaabaa", 'b', 3) = 5 StringUtils.indexOf("aabaabaa", 'b', 9) = -1 StringUtils.indexOf("aabaabaa", 'b', -1) = 2
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChar - the character to find
  
  startPos - the start position, negative treated as zero
  
  Returns:
  
  the first index of the search character, -1 if no match or null string input
  
  Since:
  
  2.0
- indexOf
  public static int indexOf(String str, String searchStr)
  
  Finds the first index within a String, handling null. This method uses String.indexOf(String).
  
  A null String will return -1.
  
  StringUtils.indexOf(null, *) = -1 StringUtils.indexOf(*, null) = -1 StringUtils.indexOf("", "") = 0 StringUtils.indexOf("", *) = -1 (except when * = "") StringUtils.indexOf("aabaabaa", "a") = 0 StringUtils.indexOf("aabaabaa", "b") = 2 StringUtils.indexOf("aabaabaa", "ab") = 1 StringUtils.indexOf("aabaabaa", "") = 0
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.0
- ordinalIndexOf
  public static int ordinalIndexOf(String str, String searchStr, int ordinal)
  
  Finds the n-th index within a String, handling null. This method uses String.indexOf(String).
  
  A null String will return -1.
  
  StringUtils.ordinalIndexOf(null, *, *) = -1 StringUtils.ordinalIndexOf(*, null, *) = -1 StringUtils.ordinalIndexOf("", "", *) = 0 StringUtils.ordinalIndexOf("aabaabaa", "a", 1) = 0 StringUtils.ordinalIndexOf("aabaabaa", "a", 2) = 1 StringUtils.ordinalIndexOf("aabaabaa", "b", 1) = 2 StringUtils.ordinalIndexOf("aabaabaa", "b", 2) = 5 StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1 StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4 StringUtils.ordinalIndexOf("aabaabaa", "", 1) = 0 StringUtils.ordinalIndexOf("aabaabaa", "", 2) = 0
  
  Note that 'head(String str, int n)' may be implemented as:
  
  str.substring(0, lastOrdinalIndexOf(str, "\n", n))
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  ordinal - the n-th searchStr to find
  
  Returns:
  
  the n-th index of the search String, -1 (INDEX_NOT_FOUND) if no match or null string input
  
  Since:
  
  2.1
- indexOf
  public static int indexOf(String str, String searchStr, int startPos)
  
  Finds the first index within a String, handling null. This method uses String.indexOf(String, int).
  
  A null String will return -1. A negative start position is treated as zero. An empty ("") search String always matches. A start position greater than the string length only matches an empty search String.
  
  StringUtils.indexOf(null, *, *) = -1 StringUtils.indexOf(*, null, *) = -1 StringUtils.indexOf("", "", 0) = 0 StringUtils.indexOf("", *, 0) = -1 (except when * = "") StringUtils.indexOf("aabaabaa", "a", 0) = 0 StringUtils.indexOf("aabaabaa", "b", 0) = 2 StringUtils.indexOf("aabaabaa", "ab", 0) = 1 StringUtils.indexOf("aabaabaa", "b", 3) = 5 StringUtils.indexOf("aabaabaa", "b", 9) = -1 StringUtils.indexOf("aabaabaa", "b", -1) = 2 StringUtils.indexOf("aabaabaa", "", 2) = 2 StringUtils.indexOf("abc", "", 9) = 3
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  startPos - the start position, negative treated as zero
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.0
- indexOfIgnoreCase
  public static int indexOfIgnoreCase(String str, String searchStr)
  
  Case in-sensitive find of the first index within a String.
  
  A null String will return -1. A negative start position is treated as zero. An empty ("") search String always matches. A start position greater than the string length only matches an empty search String.
  
  StringUtils.indexOfIgnoreCase(null, *) = -1 StringUtils.indexOfIgnoreCase(*, null) = -1 StringUtils.indexOfIgnoreCase("", "") = 0 StringUtils.indexOfIgnoreCase("aabaabaa", "a") = 0 StringUtils.indexOfIgnoreCase("aabaabaa", "b") = 2 StringUtils.indexOfIgnoreCase("aabaabaa", "ab") = 1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.5
- indexOfIgnoreCase
  public static int indexOfIgnoreCase(String str, String searchStr, int startPos)
  
  Case in-sensitive find of the first index within a String from the specified position.
  
  A null String will return -1. A negative start position is treated as zero. An empty ("") search String always matches. A start position greater than the string length only matches an empty search String.
  
  StringUtils.indexOfIgnoreCase(null, *, *) = -1 StringUtils.indexOfIgnoreCase(*, null, *) = -1 StringUtils.indexOfIgnoreCase("", "", 0) = 0 StringUtils.indexOfIgnoreCase("aabaabaa", "A", 0) = 0 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 0) = 2 StringUtils.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 3) = 5 StringUtils.indexOfIgnoreCase("aabaabaa", "B", 9) = -1 StringUtils.indexOfIgnoreCase("aabaabaa", "B", -1) = 2 StringUtils.indexOfIgnoreCase("aabaabaa", "", 2) = 2 StringUtils.indexOfIgnoreCase("abc", "", 9) = 3
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  startPos - the start position, negative treated as zero
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.5
- lastIndexOf
  public static int lastIndexOf(String str, char searchChar)
  
  Finds the last index within a String, handling null. This method uses String.lastIndexOf(int).
  
  A null or empty ("") String will return -1.
  
  StringUtils.lastIndexOf(null, *) = -1 StringUtils.lastIndexOf("", *) = -1 StringUtils.lastIndexOf("aabaabaa", 'a') = 7 StringUtils.lastIndexOf("aabaabaa", 'b') = 5
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChar - the character to find
  
  Returns:
  
  the last index of the search character, -1 if no match or null string input
  
  Since:
  
  2.0
- lastIndexOf
  public static int lastIndexOf(String str, char searchChar, int startPos)
  
  Finds the last index within a String from a start position, handling null. This method uses String.lastIndexOf(int, int).
  
  A null or empty ("") String will return -1. A negative start position returns -1. A start position greater than the string length searches the whole string.
  
  StringUtils.lastIndexOf(null, *, *) = -1 StringUtils.lastIndexOf("", *, *) = -1 StringUtils.lastIndexOf("aabaabaa", 'b', 8) = 5 StringUtils.lastIndexOf("aabaabaa", 'b', 4) = 2 StringUtils.lastIndexOf("aabaabaa", 'b', 0) = -1 StringUtils.lastIndexOf("aabaabaa", 'b', 9) = 5 StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1 StringUtils.lastIndexOf("aabaabaa", 'a', 0) = 0
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChar - the character to find
  
  startPos - the start position
  
  Returns:
  
  the last index of the search character, -1 if no match or null string input
  
  Since:
  
  2.0
- lastIndexOf
  public static int lastIndexOf(String str, String searchStr)
  
  Finds the last index within a String, handling null. This method uses String.lastIndexOf(String).
  
  A null String will return -1.
  
  StringUtils.lastIndexOf(null, *) = -1 StringUtils.lastIndexOf(*, null) = -1 StringUtils.lastIndexOf("", "") = 0 StringUtils.lastIndexOf("aabaabaa", "a") = 7 StringUtils.lastIndexOf("aabaabaa", "b") = 5 StringUtils.lastIndexOf("aabaabaa", "ab") = 4 StringUtils.lastIndexOf("aabaabaa", "") = 8
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  the last index of the search String, -1 if no match or null string input
  
  Since:
  
  2.0
- lastOrdinalIndexOf
  public static int lastOrdinalIndexOf(String str, String searchStr, int ordinal)
  
  Finds the n-th last index within a String, handling null. This method uses String.lastIndexOf(String).
  
  A null String will return -1.
  
  StringUtils.lastOrdinalIndexOf(null, *, *) = -1 StringUtils.lastOrdinalIndexOf(*, null, *) = -1 StringUtils.lastOrdinalIndexOf("", "", *) = 0 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 1) = 7 StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 2) = 6 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 1) = 5 StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 2) = 2 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 1) = 4 StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 2) = 1 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 1) = 8 StringUtils.lastOrdinalIndexOf("aabaabaa", "", 2) = 8
  
  Note that 'tail(String str, int n)' may be implemented as:
  
  str.substring(lastOrdinalIndexOf(str, "\n", n) + 1)
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  ordinal - the n-th last searchStr to find
  
  Returns:
  
  the n-th last index of the search String, -1 (INDEX_NOT_FOUND) if no match or null string input
  
  Since:
  
  2.5
- lastIndexOf
  public static int lastIndexOf(String str, String searchStr, int startPos)
  
  Finds the first index within a String, handling null. This method uses String.lastIndexOf(String, int).
  
  A null String will return -1. A negative start position returns -1. An empty ("") search String always matches unless the start position is negative. A start position greater than the string length searches the whole string.
  
  StringUtils.lastIndexOf(null, *, *) = -1 StringUtils.lastIndexOf(*, null, *) = -1 StringUtils.lastIndexOf("aabaabaa", "a", 8) = 7 StringUtils.lastIndexOf("aabaabaa", "b", 8) = 5 StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4 StringUtils.lastIndexOf("aabaabaa", "b", 9) = 5 StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1 StringUtils.lastIndexOf("aabaabaa", "a", 0) = 0 StringUtils.lastIndexOf("aabaabaa", "b", 0) = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  startPos - the start position, negative treated as zero
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.0
- lastIndexOfIgnoreCase
  public static int lastIndexOfIgnoreCase(String str, String searchStr)
  
  Case in-sensitive find of the last index within a String.
  
  A null String will return -1. A negative start position returns -1. An empty ("") search String always matches unless the start position is negative. A start position greater than the string length searches the whole string.
  
  StringUtils.lastIndexOfIgnoreCase(null, *) = -1 StringUtils.lastIndexOfIgnoreCase(*, null) = -1 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A") = 7 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B") = 5 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB") = 4
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.5
- lastIndexOfIgnoreCase
  public static int lastIndexOfIgnoreCase(String str, String searchStr, int startPos)
  
  Case in-sensitive find of the last index within a String from the specified position.
  
  A null String will return -1. A negative start position returns -1. An empty ("") search String always matches unless the start position is negative. A start position greater than the string length searches the whole string.
  
  StringUtils.lastIndexOfIgnoreCase(null, *, *) = -1 StringUtils.lastIndexOfIgnoreCase(*, null, *) = -1 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 8) = 7 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 8) = 5 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB", 8) = 4 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 9) = 5 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", -1) = -1 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 0) = 0 StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 0) = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  startPos - the start position
  
  Returns:
  
  the first index of the search String, -1 if no match or null string input
  
  Since:
  
  2.5
- contains
  public static boolean contains(String str, char searchChar)
  
  Checks if String contains a search character, handling null. This method uses String.indexOf(int).
  
  A null or empty ("") String will return false.
  
  StringUtils.contains(null, *) = false StringUtils.contains("", *) = false StringUtils.contains("abc", 'a') = true StringUtils.contains("abc", 'z') = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChar - the character to find
  
  Returns:
  
  true if the String contains the search character, false if not or null string input
  
  Since:
  
  2.0
- contains
  public static boolean contains(String str, String searchStr)
  
  Checks if String contains a search String, handling null. This method uses String.indexOf(String).
  
  A null String will return false.
  
  StringUtils.contains(null, *) = false StringUtils.contains(*, null) = false StringUtils.contains("", "") = true StringUtils.contains("abc", "") = true StringUtils.contains("abc", "a") = true StringUtils.contains("abc", "z") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  true if the String contains the search String, false if not or null string input
  
  Since:
  
  2.0
- containsIgnoreCase
  public static boolean containsIgnoreCase(String str, String searchStr)
  
  Checks if String contains a search String irrespective of case, handling null. Case-insensitivity is defined as by String.equalsIgnoreCase(String).
  A null String will return false.
  
  StringUtils.contains(null, *) = false StringUtils.contains(*, null) = false StringUtils.contains("", "") = true StringUtils.contains("abc", "") = true StringUtils.contains("abc", "a") = true StringUtils.contains("abc", "z") = false StringUtils.contains("abc", "A") = true StringUtils.contains("abc", "Z") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStr - the String to find, may be null
  
  Returns:
  
  true if the String contains the search String irrespective of case or false if not or null string input
- indexOfAny
  public static int indexOfAny(String str, char[] searchChars)
  
  Search a String to find the first index of any character in the given set of characters.
  
  A null String will return -1. A null or zero length search array will return -1.
  
  StringUtils.indexOfAny(null, *) = -1 StringUtils.indexOfAny("", *) = -1 StringUtils.indexOfAny(*, null) = -1 StringUtils.indexOfAny(*, []) = -1 StringUtils.indexOfAny("zzabyycdxx",['z','a']) = 0 StringUtils.indexOfAny("zzabyycdxx",['b','y']) = 3 StringUtils.indexOfAny("aba", ['z']) = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the index of any of the chars, -1 if no match or null input
  
  Since:
  
  2.0
- indexOfAny
  public static int indexOfAny(String str, String searchChars)
  
  Search a String to find the first index of any character in the given set of characters.
  
  A null String will return -1. A null search string will return -1.
  
  StringUtils.indexOfAny(null, *) = -1 StringUtils.indexOfAny("", *) = -1 StringUtils.indexOfAny(*, null) = -1 StringUtils.indexOfAny(*, "") = -1 StringUtils.indexOfAny("zzabyycdxx", "za") = 0 StringUtils.indexOfAny("zzabyycdxx", "by") = 3 StringUtils.indexOfAny("aba","z") = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the index of any of the chars, -1 if no match or null input
  
  Since:
  
  2.0
- containsAny
  public static boolean containsAny(String str, char[] searchChars)
  
  Checks if the String contains any character in the given set of characters.
  
  A null String will return false. A null or zero length search array will return false.
  
  StringUtils.containsAny(null, *) = false StringUtils.containsAny("", *) = false StringUtils.containsAny(*, null) = false StringUtils.containsAny(*, []) = false StringUtils.containsAny("zzabyycdxx",['z','a']) = true StringUtils.containsAny("zzabyycdxx",['b','y']) = true StringUtils.containsAny("aba", ['z']) = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the true if any of the chars are found, false if no match or null input
  
  Since:
  
  2.4
- containsAny
  public static boolean containsAny(String str, String searchChars)
  
  Checks if the String contains any character in the given set of characters.
  
  A null String will return false. A null search string will return false.
  
  StringUtils.containsAny(null, *) = false StringUtils.containsAny("", *) = false StringUtils.containsAny(*, null) = false StringUtils.containsAny(*, "") = false StringUtils.containsAny("zzabyycdxx", "za") = true StringUtils.containsAny("zzabyycdxx", "by") = true StringUtils.containsAny("aba","z") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the true if any of the chars are found, false if no match or null input
  
  Since:
  
  2.4
- indexOfAnyBut
  public static int indexOfAnyBut(String str, char[] searchChars)
  
  Search a String to find the first index of any character not in the given set of characters.
  
  A null String will return -1. A null or zero length search array will return -1.
  
  StringUtils.indexOfAnyBut(null, *) = -1 StringUtils.indexOfAnyBut("", *) = -1 StringUtils.indexOfAnyBut(*, null) = -1 StringUtils.indexOfAnyBut(*, []) = -1 StringUtils.indexOfAnyBut("zzabyycdxx", new char[] {'z', 'a'} ) = 3 StringUtils.indexOfAnyBut("aba", new char[] {'z'} ) = 0 StringUtils.indexOfAnyBut("aba", new char[] {'a', 'b'} ) = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the index of any of the chars, -1 if no match or null input
  
  Since:
  
  2.0
- indexOfAnyBut
  public static int indexOfAnyBut(String str, String searchChars)
  
  Search a String to find the first index of any character not in the given set of characters.
  
  A null String will return -1. A null or empty search string will return -1.
  
  StringUtils.indexOfAnyBut(null, *) = -1 StringUtils.indexOfAnyBut("", *) = -1 StringUtils.indexOfAnyBut(*, null) = -1 StringUtils.indexOfAnyBut(*, "") = -1 StringUtils.indexOfAnyBut("zzabyycdxx", "za") = 3 StringUtils.indexOfAnyBut("zzabyycdxx", "") = -1 StringUtils.indexOfAnyBut("aba","ab") = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - the chars to search for, may be null
  
  Returns:
  
  the index of any of the chars, -1 if no match or null input
  
  Since:
  
  2.0
- containsOnly
  public static boolean containsOnly(String str, char[] valid)
  
  Checks if the String contains only certain characters.
  
  A null String will return false. A null valid character array will return false. An empty String (length()=0) always returns true.
  
  StringUtils.containsOnly(null, *) = false StringUtils.containsOnly(*, null) = false StringUtils.containsOnly("", *) = true StringUtils.containsOnly("ab", '') = false StringUtils.containsOnly("abab", 'abc') = true StringUtils.containsOnly("ab1", 'abc') = false StringUtils.containsOnly("abz", 'abc') = false
  
  Parameters:
  
  str - the String to check, may be null
  
  valid - an array of valid chars, may be null
  
  Returns:
  
  true if it only contains valid chars and is non-null
- containsOnly
  public static boolean containsOnly(String str, String validChars)
  
  Checks if the String contains only certain characters.
  
  A null String will return false. A null valid character String will return false. An empty String (length()=0) always returns true.
  
  StringUtils.containsOnly(null, *) = false StringUtils.containsOnly(*, null) = false StringUtils.containsOnly("", *) = true StringUtils.containsOnly("ab", "") = false StringUtils.containsOnly("abab", "abc") = true StringUtils.containsOnly("ab1", "abc") = false StringUtils.containsOnly("abz", "abc") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  validChars - a String of valid chars, may be null
  
  Returns:
  
  true if it only contains valid chars and is non-null
  
  Since:
  
  2.0
- containsNone
  public static boolean containsNone(String str, char[] searchChars)
  
  Checks that the String does not contain certain characters.
  
  A null String will return true. A null invalid character array will return true. An empty String (length()=0) always returns true.
  
  StringUtils.containsNone(null, *) = true StringUtils.containsNone(*, null) = true StringUtils.containsNone("", *) = true StringUtils.containsNone("ab", '') = true StringUtils.containsNone("abab", 'xyz') = true StringUtils.containsNone("ab1", 'xyz') = true StringUtils.containsNone("abz", 'xyz') = false
  
  Parameters:
  
  str - the String to check, may be null
  
  searchChars - an array of invalid chars, may be null
  
  Returns:
  
  true if it contains none of the invalid chars, or is null
  
  Since:
  
  2.0
- containsNone
  public static boolean containsNone(String str, String invalidChars)
  
  Checks that the String does not contain certain characters.
  
  A null String will return true. A null invalid character array will return true. An empty String ("") always returns true.
  
  StringUtils.containsNone(null, *) = true StringUtils.containsNone(*, null) = true StringUtils.containsNone("", *) = true StringUtils.containsNone("ab", "") = true StringUtils.containsNone("abab", "xyz") = true StringUtils.containsNone("ab1", "xyz") = true StringUtils.containsNone("abz", "xyz") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  invalidChars - a String of invalid chars, may be null
  
  Returns:
  
  true if it contains none of the invalid chars, or is null
  
  Since:
  
  2.0
- indexOfAny
  public static int indexOfAny(String str, String[] searchStrs)
  
  Find the first index of any of a set of potential substrings.
  
  A null String will return -1. A null or zero length search array will return -1. A null search array entry will be ignored, but a search array containing "" will return 0 if str is not null. This method uses String.indexOf(String).
  
  StringUtils.indexOfAny(null, *) = -1 StringUtils.indexOfAny(*, null) = -1 StringUtils.indexOfAny(*, []) = -1 StringUtils.indexOfAny("zzabyycdxx", ["ab","cd"]) = 2 StringUtils.indexOfAny("zzabyycdxx", ["cd","ab"]) = 2 StringUtils.indexOfAny("zzabyycdxx", ["mn","op"]) = -1 StringUtils.indexOfAny("zzabyycdxx", ["zab","aby"]) = 1 StringUtils.indexOfAny("zzabyycdxx", [""]) = 0 StringUtils.indexOfAny("", [""]) = 0 StringUtils.indexOfAny("", ["a"]) = -1
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStrs - the Strings to search for, may be null
  
  Returns:
  
  the first index of any of the searchStrs in str, -1 if no match
- lastIndexOfAny
  public static int lastIndexOfAny(String str, String[] searchStrs)
  
  Find the latest index of any of a set of potential substrings.
  
  A null String will return -1. A null search array will return -1. A null or zero length search array entry will be ignored, but a search array containing "" will return the length of str if str is not null. This method uses String.indexOf(String)
  
  StringUtils.lastIndexOfAny(null, *) = -1 StringUtils.lastIndexOfAny(*, null) = -1 StringUtils.lastIndexOfAny(*, []) = -1 StringUtils.lastIndexOfAny(*, [null]) = -1 StringUtils.lastIndexOfAny("zzabyycdxx", ["ab","cd"]) = 6 StringUtils.lastIndexOfAny("zzabyycdxx", ["cd","ab"]) = 6 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1 StringUtils.lastIndexOfAny("zzabyycdxx", ["mn",""]) = 10
  
  Parameters:
  
  str - the String to check, may be null
  
  searchStrs - the Strings to search for, may be null
  
  Returns:
  
  the last index of any of the Strings, -1 if no match
- substring
  public static String substring(String str, int start)
  
  Gets a substring from the specified String avoiding exceptions.
  
  A negative start position can be used to start n characters from the end of the String.
  
  A null String will return null. An empty ("") String will return "".
  
  StringUtils.substring(null, *) = null StringUtils.substring("", *) = "" StringUtils.substring("abc", 0) = "abc" StringUtils.substring("abc", 2) = "c" StringUtils.substring("abc", 4) = "" StringUtils.substring("abc", -2) = "bc" StringUtils.substring("abc", -4) = "abc"
  
  Parameters:
  
  str - the String to get the substring from, may be null
  
  start - the position to start from, negative means count back from the end of the String by this many characters
  
  Returns:
  
  substring from start position, null if null String input
- substring
  public static String substring(String str, int start, int end)
  
  Gets a substring from the specified String avoiding exceptions.
  
  A negative start position can be used to start/end n characters from the end of the String.
  
  The returned substring starts with the character in the start position and ends before the end position. All position counting is zero-based -- i.e., to start at the beginning of the string use start = 0. Negative start and end positions can be used to specify offsets relative to the end of the String.
  
  If start is not strictly to the left of end, "" is returned.
  
  StringUtils.substring(null, *, *) = null StringUtils.substring("", * , *) = ""; StringUtils.substring("abc", 0, 2) = "ab" StringUtils.substring("abc", 2, 0) = "" StringUtils.substring("abc", 2, 4) = "c" StringUtils.substring("abc", 4, 6) = "" StringUtils.substring("abc", 2, 2) = "" StringUtils.substring("abc", -2, -1) = "b" StringUtils.substring("abc", -4, 2) = "ab"
  
  Parameters:
  
  str - the String to get the substring from, may be null
  
  start - the position to start from, negative means count back from the end of the String by this many characters
  
  end - the position to end at (exclusive), negative means count back from the end of the String by this many characters
  
  Returns:
  
  substring from start position to end positon, null if null String input
- left
  public static String left(String str, int len)
  
  Gets the leftmost len characters of a String.
  
  If len characters are not available, or the String is null, the String will be returned without an exception. An empty String is returned if len is negative.
  
  StringUtils.left(null, *) = null StringUtils.left(*, -ve) = "" StringUtils.left("", *) = "" StringUtils.left("abc", 0) = "" StringUtils.left("abc", 2) = "ab" StringUtils.left("abc", 4) = "abc"
  
  Parameters:
  
  str - the String to get the leftmost characters from, may be null
  
  len - the length of the required String
  
  Returns:
  
  the leftmost characters, null if null String input
- right
  public static String right(String str, int len)
  
  Gets the rightmost len characters of a String.
  
  If len characters are not available, or the String is null, the String will be returned without an an exception. An empty String is returned if len is negative.
  
  StringUtils.right(null, *) = null StringUtils.right(*, -ve) = "" StringUtils.right("", *) = "" StringUtils.right("abc", 0) = "" StringUtils.right("abc", 2) = "bc" StringUtils.right("abc", 4) = "abc"
  
  Parameters:
  
  str - the String to get the rightmost characters from, may be null
  
  len - the length of the required String
  
  Returns:
  
  the rightmost characters, null if null String input
- mid
  public static String mid(String str, int pos, int len)
  
  Gets len characters from the middle of a String.
  
  If len characters are not available, the remainder of the String will be returned without an exception. If the String is null, null will be returned. An empty String is returned if len is negative or exceeds the length of str.
  
  StringUtils.mid(null, *, *) = null StringUtils.mid(*, *, -ve) = "" StringUtils.mid("", 0, *) = "" StringUtils.mid("abc", 0, 2) = "ab" StringUtils.mid("abc", 0, 4) = "abc" StringUtils.mid("abc", 2, 4) = "c" StringUtils.mid("abc", 4, 2) = "" StringUtils.mid("abc", -2, 2) = "ab"
  
  Parameters:
  
  str - the String to get the characters from, may be null
  
  pos - the position to start from, negative treated as zero
  
  len - the length of the required String
  
  Returns:
  
  the middle characters, null if null String input
- substringBefore
  public static String substringBefore(String str, String separator)
  
  Gets the substring before the first occurrence of a separator. The separator is not returned.
  
  A null string input will return null. An empty ("") string input will return the empty string. A null separator will return the input string.
  
  If nothing is found, the string input is returned.
  
  StringUtils.substringBefore(null, *) = null StringUtils.substringBefore("", *) = "" StringUtils.substringBefore("abc", "a") = "" StringUtils.substringBefore("abcba", "b") = "a" StringUtils.substringBefore("abc", "c") = "ab" StringUtils.substringBefore("abc", "d") = "abc" StringUtils.substringBefore("abc", "") = "" StringUtils.substringBefore("abc", null) = "abc"
  
  Parameters:
  
  str - the String to get a substring from, may be null
  
  separator - the String to search for, may be null
  
  Returns:
  
  the substring before the first occurrence of the separator, null if null String input
  
  Since:
  
  2.0
- substringAfter
  public static String substringAfter(String str, String separator)
  
  Gets the substring after the first occurrence of a separator. The separator is not returned.
  
  A null string input will return null. An empty ("") string input will return the empty string. A null separator will return the empty string if the input string is not null.
  
  If nothing is found, the empty string is returned.
  
  StringUtils.substringAfter(null, *) = null StringUtils.substringAfter("", *) = "" StringUtils.substringAfter(*, null) = "" StringUtils.substringAfter("abc", "a") = "bc" StringUtils.substringAfter("abcba", "b") = "cba" StringUtils.substringAfter("abc", "c") = "" StringUtils.substringAfter("abc", "d") = "" StringUtils.substringAfter("abc", "") = "abc"
  
  Parameters:
  
  str - the String to get a substring from, may be null
  
  separator - the String to search for, may be null
  
  Returns:
  
  the substring after the first occurrence of the separator, null if null String input
  
  Since:
  
  2.0
- substringBeforeLast
  public static String substringBeforeLast(String str, String separator)
  
  Gets the substring before the last occurrence of a separator. The separator is not returned.
  
  A null string input will return null. An empty ("") string input will return the empty string. An empty or null separator will return the input string.
  
  If nothing is found, the string input is returned.
  
  StringUtils.substringBeforeLast(null, *) = null StringUtils.substringBeforeLast("", *) = "" StringUtils.substringBeforeLast("abcba", "b") = "abc" StringUtils.substringBeforeLast("abc", "c") = "ab" StringUtils.substringBeforeLast("a", "a") = "" StringUtils.substringBeforeLast("a", "z") = "a" StringUtils.substringBeforeLast("a", null) = "a" StringUtils.substringBeforeLast("a", "") = "a"
  
  Parameters:
  
  str - the String to get a substring from, may be null
  
  separator - the String to search for, may be null
  
  Returns:
  
  the substring before the last occurrence of the separator, null if null String input
  
  Since:
  
  2.0
- substringAfterLast
  public static String substringAfterLast(String str, String separator)
  
  Gets the substring after the last occurrence of a separator. The separator is not returned.
  
  A null string input will return null. An empty ("") string input will return the empty string. An empty or null separator will return the empty string if the input string is not null.
  
  If nothing is found, the empty string is returned.
  
  StringUtils.substringAfterLast(null, *) = null StringUtils.substringAfterLast("", *) = "" StringUtils.substringAfterLast(*, "") = "" StringUtils.substringAfterLast(*, null) = "" StringUtils.substringAfterLast("abc", "a") = "bc" StringUtils.substringAfterLast("abcba", "b") = "a" StringUtils.substringAfterLast("abc", "c") = "" StringUtils.substringAfterLast("a", "a") = "" StringUtils.substringAfterLast("a", "z") = ""
  
  Parameters:
  
  str - the String to get a substring from, may be null
  
  separator - the String to search for, may be null
  
  Returns:
  
  the substring after the last occurrence of the separator, null if null String input
  
  Since:
  
  2.0
- substringBetween
  public static String substringBetween(String str, String tag)
  
  Gets the String that is nested in between two instances of the same String.
  
  A null input String returns null. A null tag returns null.
  
  StringUtils.substringBetween(null, *) = null StringUtils.substringBetween("", "") = "" StringUtils.substringBetween("", "tag") = null StringUtils.substringBetween("tagabctag", null) = null StringUtils.substringBetween("tagabctag", "") = "" StringUtils.substringBetween("tagabctag", "tag") = "abc"
  
  Parameters:
  
  str - the String containing the substring, may be null
  
  tag - the String before and after the substring, may be null
  
  Returns:
  
  the substring, null if no match
  
  Since:
  
  2.0
- substringBetween
  public static String substringBetween(String str, String open, String close)
  
  Gets the String that is nested in between two Strings. Only the first match is returned.
  
  A null input String returns null. A null open/close returns null (no match). An empty ("") open and close returns an empty string.
  
  StringUtils.substringBetween("wx[b]yz", "[", "]") = "b" StringUtils.substringBetween(null, *, *) = null StringUtils.substringBetween(*, null, *) = null StringUtils.substringBetween(*, *, null) = null StringUtils.substringBetween("", "", "") = "" StringUtils.substringBetween("", "", "]") = null StringUtils.substringBetween("", "[", "]") = null StringUtils.substringBetween("yabcz", "", "") = "" StringUtils.substringBetween("yabcz", "y", "z") = "abc" StringUtils.substringBetween("yabczyabcz", "y", "z") = "abc"
  
  Parameters:
  
  str - the String containing the substring, may be null
  
  open - the String before the substring, may be null
  
  close - the String after the substring, may be null
  
  Returns:
  
  the substring, null if no match
  
  Since:
  
  2.0
- substringsBetween
  public static String[] substringsBetween(String str, String open, String close)
  
  Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.
  
  A null input String returns null. A null open/close returns null (no match). An empty ("") open/close returns null (no match).
  
  StringUtils.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"] StringUtils.substringsBetween(null, *, *) = null StringUtils.substringsBetween(*, null, *) = null StringUtils.substringsBetween(*, *, null) = null StringUtils.substringsBetween("", "[", "]") = []
  
  Parameters:
  
  str - the String containing the substrings, null returns null, empty returns empty
  
  open - the String identifying the start of the substring, empty returns null
  
  close - the String identifying the end of the substring, empty returns null
  
  Returns:
  
  a String Array of substrings, or null if no match
  
  Since:
  
  2.3
- getNestedString
  public static String getNestedString(String str, String tag)
  
  Deprecated.
  Use the better named substringBetween(String, String). Method will be removed in Commons Lang 3.0.
  
  Gets the String that is nested in between two instances of the same String.
  
  A null input String returns null. A null tag returns null.
  
  StringUtils.getNestedString(null, *) = null StringUtils.getNestedString("", "") = "" StringUtils.getNestedString("", "tag") = null StringUtils.getNestedString("tagabctag", null) = null StringUtils.getNestedString("tagabctag", "") = "" StringUtils.getNestedString("tagabctag", "tag") = "abc"
  
  Parameters:
  
  str - the String containing nested-string, may be null
  
  tag - the String before and after nested-string, may be null
  
  Returns:
  
  the nested String, null if no match
- getNestedString
  public static String getNestedString(String str, String open, String close)
  
  Deprecated.
  Use the better named substringBetween(String, String, String). Method will be removed in Commons Lang 3.0.
  
  Gets the String that is nested in between two Strings. Only the first match is returned.
  
  A null input String returns null. A null open/close returns null (no match). An empty ("") open/close returns an empty string.
  
  StringUtils.getNestedString(null, *, *) = null StringUtils.getNestedString("", "", "") = "" StringUtils.getNestedString("", "", "tag") = null StringUtils.getNestedString("", "tag", "tag") = null StringUtils.getNestedString("yabcz", null, null) = null StringUtils.getNestedString("yabcz", "", "") = "" StringUtils.getNestedString("yabcz", "y", "z") = "abc" StringUtils.getNestedString("yabczyabcz", "y", "z") = "abc"
  
  Parameters:
  
  str - the String containing nested-string, may be null
  
  open - the String before nested-string, may be null
  
  close - the String after nested-string, may be null
  
  Returns:
  
  the nested String, null if no match
- split
  public static String[] split(String str)
  
  Splits the provided text into an array, using whitespace as the separator. Whitespace is defined by Character.isWhitespace(char).
  
  The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
  
  A null input String returns null.
  
  StringUtils.split(null) = null StringUtils.split("") = [] StringUtils.split("abc def") = ["abc", "def"] StringUtils.split("abc def") = ["abc", "def"] StringUtils.split(" abc ") = ["abc"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  Returns:
  
  an array of parsed Strings, null if null String input
- split
  public static String[] split(String str, char separatorChar)
  
  Splits the provided text into an array, separator specified. This is an alternative to using StringTokenizer.
  
  The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
  
  A null input String returns null.
  
  StringUtils.split(null, *) = null StringUtils.split("", *) = [] StringUtils.split("a.b.c", '.') = ["a", "b", "c"] StringUtils.split("a..b.c", '.') = ["a", "b", "c"] StringUtils.split("a:b:c", '.') = ["a:b:c"] StringUtils.split("a b c", ' ') = ["a", "b", "c"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChar - the character used as the delimiter
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.0
- split
  public static String[] split(String str, String separatorChars)
  
  Splits the provided text into an array, separators specified. This is an alternative to using StringTokenizer.
  
  The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
  
  A null input String returns null. A null separatorChars splits on whitespace.
  
  StringUtils.split(null, *) = null StringUtils.split("", *) = [] StringUtils.split("abc def", null) = ["abc", "def"] StringUtils.split("abc def", " ") = ["abc", "def"] StringUtils.split("abc def", " ") = ["abc", "def"] StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChars - the characters used as the delimiters, null splits on whitespace
  
  Returns:
  
  an array of parsed Strings, null if null String input
- split
  public static String[] split(String str, String separatorChars, int max)
  
  Splits the provided text into an array with a maximum length, separators specified.
  
  The separator is not included in the returned String array. Adjacent separators are treated as one separator.
  
  A null input String returns null. A null separatorChars splits on whitespace.
  
  If more than max delimited substrings are found, the last returned string includes all characters after the first max - 1 returned strings (including separator characters).
  
  StringUtils.split(null, *, *) = null StringUtils.split("", *, *) = [] StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"] StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"] StringUtils.split("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"] StringUtils.split("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChars - the characters used as the delimiters, null splits on whitespace
  
  max - the maximum number of elements to include in the array. A zero or negative value implies no limit
  
  Returns:
  
  an array of parsed Strings, null if null String input
- splitByWholeSeparator
  public static String[] splitByWholeSeparator(String str, String separator)
  
  Splits the provided text into an array, separator string specified.
  
  The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.
  
  A null input String returns null. A null separator splits on whitespace.
  
  StringUtils.splitByWholeSeparator(null, *) = null StringUtils.splitByWholeSeparator("", *) = [] StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparator("ab:cd:ef", ":") = ["ab", "cd", "ef"] StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separator - String containing the String to be used as a delimiter, null splits on whitespace
  
  Returns:
  
  an array of parsed Strings, null if null String was input
- splitByWholeSeparator
  public static String[] splitByWholeSeparator(String str, String separator, int max)
  
  Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.
  
  The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.
  
  A null input String returns null. A null separator splits on whitespace.
  
  StringUtils.splitByWholeSeparator(null, *, *) = null StringUtils.splitByWholeSeparator("", *, *) = [] StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"] StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separator - String containing the String to be used as a delimiter, null splits on whitespace
  
  max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
  
  Returns:
  
  an array of parsed Strings, null if null String was input
- splitByWholeSeparatorPreserveAllTokens
  public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator)
  
  Splits the provided text into an array, separator string specified.
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
  
  A null input String returns null. A null separator splits on whitespace.
  
  StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *) = null StringUtils.splitByWholeSeparatorPreserveAllTokens("", *) = [] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null) = ["ab", "", "", "de", "fg"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":") = ["ab", "cd", "ef"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separator - String containing the String to be used as a delimiter, null splits on whitespace
  
  Returns:
  
  an array of parsed Strings, null if null String was input
  
  Since:
  
  2.4
- splitByWholeSeparatorPreserveAllTokens
  public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator, int max)
  
  Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
  
  A null input String returns null. A null separator splits on whitespace.
  
  StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *, *) = null StringUtils.splitByWholeSeparatorPreserveAllTokens("", *, *) = [] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0) = ["ab", "de", "fg"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0) = ["ab", "", "", "de", "fg"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"] StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separator - String containing the String to be used as a delimiter, null splits on whitespace
  
  max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
  
  Returns:
  
  an array of parsed Strings, null if null String was input
  
  Since:
  
  2.4
- splitPreserveAllTokens
  public static String[] splitPreserveAllTokens(String str)
  
  Splits the provided text into an array, using whitespace as the separator, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer. Whitespace is defined by Character.isWhitespace(char).
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
  
  A null input String returns null.
  
  StringUtils.splitPreserveAllTokens(null) = null StringUtils.splitPreserveAllTokens("") = [] StringUtils.splitPreserveAllTokens("abc def") = ["abc", "def"] StringUtils.splitPreserveAllTokens("abc def") = ["abc", "", "def"] StringUtils.splitPreserveAllTokens(" abc ") = ["", "abc", ""]
  
  Parameters:
  
  str - the String to parse, may be null
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.1
- splitPreserveAllTokens
  public static String[] splitPreserveAllTokens(String str, char separatorChar)
  
  Splits the provided text into an array, separator specified, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer.
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
  
  A null input String returns null.
  
  StringUtils.splitPreserveAllTokens(null, *) = null StringUtils.splitPreserveAllTokens("", *) = [] StringUtils.splitPreserveAllTokens("a.b.c", '.') = ["a", "b", "c"] StringUtils.splitPreserveAllTokens("a..b.c", '.') = ["a", "", "b", "c"] StringUtils.splitPreserveAllTokens("a:b:c", '.') = ["a:b:c"] StringUtils.splitPreserveAllTokens("a\tb\nc", null) = ["a", "b", "c"] StringUtils.splitPreserveAllTokens("a b c", ' ') = ["a", "b", "c"] StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", ""] StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", "", ""] StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", a", "b", "c"] StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", "", a", "b", "c"] StringUtils.splitPreserveAllTokens(" a b c ", ' ') = ["", a", "b", "c", ""]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChar - the character used as the delimiter, null splits on whitespace
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.1
- splitPreserveAllTokens
  public static String[] splitPreserveAllTokens(String str, String separatorChars)
  
  Splits the provided text into an array, separators specified, preserving all tokens, including empty tokens created by adjacent separators. This is an alternative to using StringTokenizer.
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
  
  A null input String returns null. A null separatorChars splits on whitespace.
  
  StringUtils.splitPreserveAllTokens(null, *) = null StringUtils.splitPreserveAllTokens("", *) = [] StringUtils.splitPreserveAllTokens("abc def", null) = ["abc", "def"] StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "def"] StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "", def"] StringUtils.splitPreserveAllTokens("ab:cd:ef", ":") = ["ab", "cd", "ef"] StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":") = ["ab", "cd", "ef", ""] StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""] StringUtils.splitPreserveAllTokens("ab::cd:ef", ":") = ["ab", "", cd", "ef"] StringUtils.splitPreserveAllTokens(":cd:ef", ":") = ["", cd", "ef"] StringUtils.splitPreserveAllTokens("::cd:ef", ":") = ["", "", cd", "ef"] StringUtils.splitPreserveAllTokens(":cd:ef:", ":") = ["", cd", "ef", ""]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChars - the characters used as the delimiters, null splits on whitespace
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.1
- splitPreserveAllTokens
  public static String[] splitPreserveAllTokens(String str, String separatorChars, int max)
  
  Splits the provided text into an array with a maximum length, separators specified, preserving all tokens, including empty tokens created by adjacent separators.
  
  The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. Adjacent separators are treated as one separator.
  
  A null input String returns null. A null separatorChars splits on whitespace.
  
  If more than max delimited substrings are found, the last returned string includes all characters after the first max - 1 returned strings (including separator characters).
  
  StringUtils.splitPreserveAllTokens(null, *, *) = null StringUtils.splitPreserveAllTokens("", *, *) = [] StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"] StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"] StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"] StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] StringUtils.splitPreserveAllTokens("ab de fg", null, 2) = ["ab", " de fg"] StringUtils.splitPreserveAllTokens("ab de fg", null, 3) = ["ab", "", " de fg"] StringUtils.splitPreserveAllTokens("ab de fg", null, 4) = ["ab", "", "", "de fg"]
  
  Parameters:
  
  str - the String to parse, may be null
  
  separatorChars - the characters used as the delimiters, null splits on whitespace
  
  max - the maximum number of elements to include in the array. A zero or negative value implies no limit
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.1
- splitByCharacterType
  public static String[] splitByCharacterType(String str)
  
  Splits a String by Character type as returned by java.lang.Character.getType(char). Groups of contiguous characters of the same type are returned as complete tokens.
  StringUtils.splitByCharacterType(null) = null StringUtils.splitByCharacterType("") = [] StringUtils.splitByCharacterType("ab de fg") = ["ab", " ", "de", " ", "fg"] StringUtils.splitByCharacterType("ab de fg") = ["ab", " ", "de", " ", "fg"] StringUtils.splitByCharacterType("ab:cd:ef") = ["ab", ":", "cd", ":", "ef"] StringUtils.splitByCharacterType("number5") = ["number", "5"] StringUtils.splitByCharacterType("fooBar") = ["foo", "B", "ar"] StringUtils.splitByCharacterType("foo200Bar") = ["foo", "200", "B", "ar"] StringUtils.splitByCharacterType("ASFRules") = ["ASFR", "ules"]
  
  Parameters:
  
  str - the String to split, may be null
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.4
- splitByCharacterTypeCamelCase
  public static String[] splitByCharacterTypeCamelCase(String str)
  
  Splits a String by Character type as returned by java.lang.Character.getType(char). Groups of contiguous characters of the same type are returned as complete tokens, with the following exception: the character of type Character.UPPERCASE_LETTER, if any, immediately preceding a token of type Character.LOWERCASE_LETTER will belong to the following token rather than to the preceding, if any, Character.UPPERCASE_LETTER token.
  StringUtils.splitByCharacterTypeCamelCase(null) = null StringUtils.splitByCharacterTypeCamelCase("") = [] StringUtils.splitByCharacterTypeCamelCase("ab de fg") = ["ab", " ", "de", " ", "fg"] StringUtils.splitByCharacterTypeCamelCase("ab de fg") = ["ab", " ", "de", " ", "fg"] StringUtils.splitByCharacterTypeCamelCase("ab:cd:ef") = ["ab", ":", "cd", ":", "ef"] StringUtils.splitByCharacterTypeCamelCase("number5") = ["number", "5"] StringUtils.splitByCharacterTypeCamelCase("fooBar") = ["foo", "Bar"] StringUtils.splitByCharacterTypeCamelCase("foo200Bar") = ["foo", "200", "Bar"] StringUtils.splitByCharacterTypeCamelCase("ASFRules") = ["ASF", "Rules"]
  
  Parameters:
  
  str - the String to split, may be null
  
  Returns:
  
  an array of parsed Strings, null if null String input
  
  Since:
  
  2.4
- concatenate
  public static String concatenate(Object[] array)
  
  Deprecated.
  Use the better named join(Object[]) instead. Method will be removed in Commons Lang 3.0.
  
  Joins the provided elements into a single String.
  
  No separator is added to the joined String. Null objects or empty string elements are represented by empty strings.
  
  StringUtils.concatenate(null) = null StringUtils.concatenate([]) = "" StringUtils.concatenate([null]) = "" StringUtils.concatenate(["a", "b", "c"]) = "abc" StringUtils.concatenate([null, "", "a"]) = "a"
  
  Parameters:
  
  array - the array of values to concatenate, may be null
  
  Returns:
  
  the concatenated String, null if null array input
- join
  public static String join(Object[] array)
  
  Joins the elements of the provided array into a single String containing the provided list of elements.
  
  No separator is added to the joined String. Null objects or empty strings within the array are represented by empty strings.
  
  StringUtils.join(null) = null StringUtils.join([]) = "" StringUtils.join([null]) = "" StringUtils.join(["a", "b", "c"]) = "abc" StringUtils.join([null, "", "a"]) = "a"
  
  Parameters:
  
  array - the array of values to join together, may be null
  
  Returns:
  
  the joined String, null if null array input
  
  Since:
  
  2.0
- join
  public static String join(Object[] array, char separator)
  
  Joins the elements of the provided array into a single String containing the provided list of elements.
  
  No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings.
  
  StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], ';') = "a;b;c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join([null, "", "a"], ';') = ";;a"
  
  Parameters:
  
  array - the array of values to join together, may be null
  
  separator - the separator character to use
  
  Returns:
  
  the joined String, null if null array input
  
  Since:
  
  2.0
- join
  public static String join(Object[] array, char separator, int startIndex, int endIndex)
  
  Joins the elements of the provided array into a single String containing the provided list of elements.
  
  No delimiter is added before or after the list. Null objects or empty strings within the array are represented by empty strings.
  
  StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], ';') = "a;b;c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join([null, "", "a"], ';') = ";;a"
  
  Parameters:
  
  array - the array of values to join together, may be null
  
  separator - the separator character to use
  
  startIndex - the first index to start joining from. It is an error to pass in an end index past the end of the array
  
  endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
  
  Returns:
  
  the joined String, null if null array input
  
  Since:
  
  2.0
- join
  public static String join(Object[] array, String separator)
  
  Joins the elements of the provided array into a single String containing the provided list of elements.
  
  No delimiter is added before or after the list. A null separator is the same as an empty String (""). Null objects or empty strings within the array are represented by empty strings.
  
  StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], "--") = "a--b--c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join(["a", "b", "c"], "") = "abc" StringUtils.join([null, "", "a"], ',') = ",,a"
  
  Parameters:
  
  array - the array of values to join together, may be null
  
  separator - the separator character to use, null treated as ""
  
  Returns:
  
  the joined String, null if null array input
- join
  public static String join(Object[] array, String separator, int startIndex, int endIndex)
  
  Joins the elements of the provided array into a single String containing the provided list of elements.
  
  No delimiter is added before or after the list. A null separator is the same as an empty String (""). Null objects or empty strings within the array are represented by empty strings.
  
  StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], "--") = "a--b--c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join(["a", "b", "c"], "") = "abc" StringUtils.join([null, "", "a"], ',') = ",,a"
  
  Parameters:
  
  array - the array of values to join together, may be null
  
  separator - the separator character to use, null treated as ""
  
  startIndex - the first index to start joining from. It is an error to pass in an end index past the end of the array
  
  endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
  
  Returns:
  
  the joined String, null if null array input
- join
  
  public static String join(Iterator iterator, char separator)
  
  Joins the elements of the provided Iterator into a single String containing the provided elements.
  
  No delimiter is added before or after the list. Null objects or empty strings within the iteration are represented by empty strings.
  
  See the examples here: join(Object[],char).
  
  Parameters:
  
  iterator - the Iterator of values to join together, may be null
  
  separator - the separator character to use
  
  Returns:
  
  the joined String, null if null iterator input
  
  Since:
  
  2.0
- join
  
  public static String join(Iterator iterator, String separator)
  
  Joins the elements of the provided Iterator into a single String containing the provided elements.
  
  No delimiter is added before or after the list. A null separator is the same as an empty String ("").
  
  See the examples here: join(Object[],String).
  
  Parameters:
  
  iterator - the Iterator of values to join together, may be null
  
  separator - the separator character to use, null treated as ""
  
  Returns:
  
  the joined String, null if null iterator input
- join
  
  public static String join(Collection collection, char separator)
  
  Joins the elements of the provided Collection into a single String containing the provided elements.
  
  No delimiter is added before or after the list. Null objects or empty strings within the iteration are represented by empty strings.
  
  See the examples here: join(Object[],char).
  
  Parameters:
  
  collection - the Collection of values to join together, may be null
  
  separator - the separator character to use
  
  Returns:
  
  the joined String, null if null iterator input
  
  Since:
  
  2.3
- join
  
  public static String join(Collection collection, String separator)
  
  Joins the elements of the provided Collection into a single String containing the provided elements.
  
  No delimiter is added before or after the list. A null separator is the same as an empty String ("").
  
  See the examples here: join(Object[],String).
  
  Parameters:
  
  collection - the Collection of values to join together, may be null
  
  separator - the separator character to use, null treated as ""
  
  Returns:
  
  the joined String, null if null iterator input
  
  Since:
  
  2.3
- deleteSpaces
  public static String deleteSpaces(String str)
  
  Deprecated.
  Use the better localized deleteWhitespace(String). Method will be removed in Commons Lang 3.0.
  
  Deletes all 'space' characters from a String as defined by Character.isSpace(char).
  
  This is the only StringUtils method that uses the isSpace definition. You are advised to use deleteWhitespace(String) instead as whitespace is much better localized.
  
  StringUtils.deleteSpaces(null) = null StringUtils.deleteSpaces("") = "" StringUtils.deleteSpaces("abc") = "abc" StringUtils.deleteSpaces(" \t abc \n ") = "abc" StringUtils.deleteSpaces("ab c") = "abc" StringUtils.deleteSpaces("a\nb\tc ") = "abc"
  
  Spaces are defined as {' ', '\t', '\r', '\n', '\b'} in line with the deprecated isSpace method.
  
  Parameters:
  
  str - the String to delete spaces from, may be null
  
  Returns:
  
  the String without 'spaces', null if null String input
- deleteWhitespace
  public static String deleteWhitespace(String str)
  
  Deletes all whitespaces from a String as defined by Character.isWhitespace(char).
  
  StringUtils.deleteWhitespace(null) = null StringUtils.deleteWhitespace("") = "" StringUtils.deleteWhitespace("abc") = "abc" StringUtils.deleteWhitespace(" ab c ") = "abc"
  
  Parameters:
  
  str - the String to delete whitespace from, may be null
  
  Returns:
  
  the String without whitespaces, null if null String input
- removeStart
  public static String removeStart(String str, String remove)
  
  Removes a substring only if it is at the begining of a source string, otherwise returns the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
  
  StringUtils.removeStart(null, *) = null StringUtils.removeStart("", *) = "" StringUtils.removeStart(*, null) = * StringUtils.removeStart("www.domain.com", "www.") = "domain.com" StringUtils.removeStart("domain.com", "www.") = "domain.com" StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com" StringUtils.removeStart("abc", "") = "abc"
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the String to search for and remove, may be null
  
  Returns:
  
  the substring with the string removed if found, null if null String input
  
  Since:
  
  2.1
- removeStartIgnoreCase
  public static String removeStartIgnoreCase(String str, String remove)
  
  Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
  
  StringUtils.removeStartIgnoreCase(null, *) = null StringUtils.removeStartIgnoreCase("", *) = "" StringUtils.removeStartIgnoreCase(*, null) = * StringUtils.removeStartIgnoreCase("www.domain.com", "www.") = "domain.com" StringUtils.removeStartIgnoreCase("www.domain.com", "WWW.") = "domain.com" StringUtils.removeStartIgnoreCase("domain.com", "www.") = "domain.com" StringUtils.removeStartIgnoreCase("www.domain.com", "domain") = "www.domain.com" StringUtils.removeStartIgnoreCase("abc", "") = "abc"
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the String to search for (case insensitive) and remove, may be null
  
  Returns:
  
  the substring with the string removed if found, null if null String input
  
  Since:
  
  2.4
- removeEnd
  public static String removeEnd(String str, String remove)
  
  Removes a substring only if it is at the end of a source string, otherwise returns the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
  
  StringUtils.removeEnd(null, *) = null StringUtils.removeEnd("", *) = "" StringUtils.removeEnd(*, null) = * StringUtils.removeEnd("www.domain.com", ".com.") = "www.domain.com" StringUtils.removeEnd("www.domain.com", ".com") = "www.domain" StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com" StringUtils.removeEnd("abc", "") = "abc"
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the String to search for and remove, may be null
  
  Returns:
  
  the substring with the string removed if found, null if null String input
  
  Since:
  
  2.1
- removeEndIgnoreCase
  public static String removeEndIgnoreCase(String str, String remove)
  
  Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
  
  StringUtils.removeEndIgnoreCase(null, *) = null StringUtils.removeEndIgnoreCase("", *) = "" StringUtils.removeEndIgnoreCase(*, null) = * StringUtils.removeEndIgnoreCase("www.domain.com", ".com.") = "www.domain.com" StringUtils.removeEndIgnoreCase("www.domain.com", ".com") = "www.domain" StringUtils.removeEndIgnoreCase("www.domain.com", "domain") = "www.domain.com" StringUtils.removeEndIgnoreCase("abc", "") = "abc" StringUtils.removeEndIgnoreCase("www.domain.com", ".COM") = "www.domain") StringUtils.removeEndIgnoreCase("www.domain.COM", ".com") = "www.domain")
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the String to search for (case insensitive) and remove, may be null
  
  Returns:
  
  the substring with the string removed if found, null if null String input
  
  Since:
  
  2.4
- remove
  public static String remove(String str, String remove)
  
  Removes all occurrences of a substring from within the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string. A null remove string will return the source string. An empty ("") remove string will return the source string.
  
  StringUtils.remove(null, *) = null StringUtils.remove("", *) = "" StringUtils.remove(*, null) = * StringUtils.remove(*, "") = * StringUtils.remove("queued", "ue") = "qd" StringUtils.remove("queued", "zz") = "queued"
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the String to search for and remove, may be null
  
  Returns:
  
  the substring with the string removed if found, null if null String input
  
  Since:
  
  2.1
- remove
  public static String remove(String str, char remove)
  
  Removes all occurrences of a character from within the source string.
  
  A null source string will return null. An empty ("") source string will return the empty string.
  
  StringUtils.remove(null, *) = null StringUtils.remove("", *) = "" StringUtils.remove("queued", 'u') = "qeed" StringUtils.remove("queued", 'z') = "queued"
  
  Parameters:
  
  str - the source String to search, may be null
  
  remove - the char to search for and remove, may be null
  
  Returns:
  
  the substring with the char removed if found, null if null String input
  
  Since:
  
  2.1
- replaceOnce
  public static String replaceOnce(String text, String searchString, String replacement)
  
  Replaces a String with another String inside a larger String, once.
  
  A null reference passed to this method is a no-op.
  
  StringUtils.replaceOnce(null, *, *) = null StringUtils.replaceOnce("", *, *) = "" StringUtils.replaceOnce("any", null, *) = "any" StringUtils.replaceOnce("any", *, null) = "any" StringUtils.replaceOnce("any", "", *) = "any" StringUtils.replaceOnce("aba", "a", null) = "aba" StringUtils.replaceOnce("aba", "a", "") = "ba" StringUtils.replaceOnce("aba", "a", "z") = "zba"
  
  Parameters:
  
  text - text to search and replace in, may be null
  
  searchString - the String to search for, may be null
  
  replacement - the String to replace with, may be null
  
  Returns:
  
  the text with any replacements processed, null if null String input
  
  See Also:
  
  replace(String text, String searchString, String replacement, int max)
- replace
  public static String replace(String text, String searchString, String replacement)
  
  Replaces all occurrences of a String within another String.
  
  A null reference passed to this method is a no-op.
  
  StringUtils.replace(null, *, *) = null StringUtils.replace("", *, *) = "" StringUtils.replace("any", null, *) = "any" StringUtils.replace("any", *, null) = "any" StringUtils.replace("any", "", *) = "any" StringUtils.replace("aba", "a", null) = "aba" StringUtils.replace("aba", "a", "") = "b" StringUtils.replace("aba", "a", "z") = "zbz"
  
  Parameters:
  
  text - text to search and replace in, may be null
  
  searchString - the String to search for, may be null
  
  replacement - the String to replace it with, may be null
  
  Returns:
  
  the text with any replacements processed, null if null String input
  
  See Also:
  
  replace(String text, String searchString, String replacement, int max)
- replace
  public static String replace(String text, String searchString, String replacement, int max)
  
  Replaces a String with another String inside a larger String, for the first max values of the search String.
  
  A null reference passed to this method is a no-op.
  
  StringUtils.replace(null, *, *, *) = null StringUtils.replace("", *, *, *) = "" StringUtils.replace("any", null, *, *) = "any" StringUtils.replace("any", *, null, *) = "any" StringUtils.replace("any", "", *, *) = "any" StringUtils.replace("any", *, *, 0) = "any" StringUtils.replace("abaa", "a", null, -1) = "abaa" StringUtils.replace("abaa", "a", "", -1) = "b" StringUtils.replace("abaa", "a", "z", 0) = "abaa" StringUtils.replace("abaa", "a", "z", 1) = "zbaa" StringUtils.replace("abaa", "a", "z", 2) = "zbza" StringUtils.replace("abaa", "a", "z", -1) = "zbzz"
  
  Parameters:
  
  text - text to search and replace in, may be null
  
  searchString - the String to search for, may be null
  
  replacement - the String to replace it with, may be null
  
  max - maximum number of values to replace, or -1 if no maximum
  
  Returns:
  
  the text with any replacements processed, null if null String input
- replaceEach
  public static String replaceEach(String text, String[] searchList, String[] replacementList)
  
  Replaces all occurrences of Strings within another String.
  
  A null reference passed to this method is a no-op, or if any "search string" or "string to replace" is null, that replace will be ignored. This will not repeat. For repeating replaces, call the overloaded method.
  
  StringUtils.replaceEach(null, *, *) = null StringUtils.replaceEach("", *, *) = "" StringUtils.replaceEach("aba", null, null) = "aba" StringUtils.replaceEach("aba", new String[0], null) = "aba" StringUtils.replaceEach("aba", null, new String[0]) = "aba" StringUtils.replaceEach("aba", new String[]{"a"}, null) = "aba" StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""}) = "b" StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"}) = "aba" StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"}) = "wcte" (example of how it does not repeat) StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}) = "dcte"
  
  Parameters:
  
  text - text to search and replace in, no-op if null
  
  searchList - the Strings to search for, no-op if null
  
  replacementList - the Strings to replace them with, no-op if null
  
  Returns:
  
  the text with any replacements processed, null if null String input
  
  Throws:
  
  IndexOutOfBoundsException - if the lengths of the arrays are not the same (null is ok, and/or size 0)
  
  Since:
  
  2.4
- replaceEachRepeatedly
  public static String replaceEachRepeatedly(String text, String[] searchList, String[] replacementList)
  
  Replaces all occurrences of Strings within another String.
  
  A null reference passed to this method is a no-op, or if any "search string" or "string to replace" is null, that replace will be ignored. This will not repeat. For repeating replaces, call the overloaded method.
  
  StringUtils.replaceEach(null, *, *, *) = null StringUtils.replaceEach("", *, *, *) = "" StringUtils.replaceEach("aba", null, null, *) = "aba" StringUtils.replaceEach("aba", new String[0], null, *) = "aba" StringUtils.replaceEach("aba", null, new String[0], *) = "aba" StringUtils.replaceEach("aba", new String[]{"a"}, null, *) = "aba" StringUtils.replaceEach("aba", new String[]{"a"}, new String[]{""}, *) = "b" StringUtils.replaceEach("aba", new String[]{null}, new String[]{"a"}, *) = "aba" StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"w", "t"}, *) = "wcte" (example of how it repeats) StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, false) = "dcte" StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "t"}, true) = "tcte" StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}, true) = IllegalArgumentException StringUtils.replaceEach("abcde", new String[]{"ab", "d"}, new String[]{"d", "ab"}, false) = "dcabe"
  
  Parameters:
  
  text - text to search and replace in, no-op if null
  
  searchList - the Strings to search for, no-op if null
  
  replacementList - the Strings to replace them with, no-op if null
  
  Returns:
  
  the text with any replacements processed, null if null String input
  
  Throws:
  
  IllegalArgumentException - if the search is repeating and there is an endless loop due to outputs of one being inputs to another
  
  IndexOutOfBoundsException - if the lengths of the arrays are not the same (null is ok, and/or size 0)
  
  Since:
  
  2.4
- replaceChars
  public static String replaceChars(String str, char searchChar, char replaceChar)
  
  Replaces all occurrences of a character in a String with another. This is a null-safe version of String.replace(char, char).
  
  A null string input returns null. An empty ("") string input returns an empty string.
  
  StringUtils.replaceChars(null, *, *) = null StringUtils.replaceChars("", *, *) = "" StringUtils.replaceChars("abcba", 'b', 'y') = "aycya" StringUtils.replaceChars("abcba", 'z', 'y') = "abcba"
  
  Parameters:
  
  str - String to replace characters in, may be null
  
  searchChar - the character to search for, may be null
  
  replaceChar - the character to replace, may be null
  
  Returns:
  
  modified String, null if null string input
  
  Since:
  
  2.0
- replaceChars
  public static String replaceChars(String str, String searchChars, String replaceChars)
  
  Replaces multiple characters in a String in one go. This method can also be used to delete characters.
  
  For example: replaceChars("hello", "ho", "jy") = jelly.
  
  A null string input returns null. An empty ("") string input returns an empty string. A null or empty set of search characters returns the input string.
  
  The length of the search characters should normally equal the length of the replace characters. If the search characters is longer, then the extra search characters are deleted. If the search characters is shorter, then the extra replace characters are ignored.
  
  StringUtils.replaceChars(null, *, *) = null StringUtils.replaceChars("", *, *) = "" StringUtils.replaceChars("abc", null, *) = "abc" StringUtils.replaceChars("abc", "", *) = "abc" StringUtils.replaceChars("abc", "b", null) = "ac" StringUtils.replaceChars("abc", "b", "") = "ac" StringUtils.replaceChars("abcba", "bc", "yz") = "ayzya" StringUtils.replaceChars("abcba", "bc", "y") = "ayya" StringUtils.replaceChars("abcba", "bc", "yzx") = "ayzya"
  
  Parameters:
  
  str - String to replace characters in, may be null
  
  searchChars - a set of characters to search for, may be null
  
  replaceChars - a set of characters to replace, may be null
  
  Returns:
  
  modified String, null if null string input
  
  Since:
  
  2.0
- overlayString
  public static String overlayString(String text, String overlay, int start, int end)
  
  Deprecated.
  Use better named overlay(String, String, int, int) instead. Method will be removed in Commons Lang 3.0.
  
  Overlays part of a String with another String.
  
  StringUtils.overlayString(null, *, *, *) = NullPointerException StringUtils.overlayString(*, null, *, *) = NullPointerException StringUtils.overlayString("", "abc", 0, 0) = "abc" StringUtils.overlayString("abcdef", null, 2, 4) = "abef" StringUtils.overlayString("abcdef", "", 2, 4) = "abef" StringUtils.overlayString("abcdef", "zzzz", 2, 4) = "abzzzzef" StringUtils.overlayString("abcdef", "zzzz", 4, 2) = "abcdzzzzcdef" StringUtils.overlayString("abcdef", "zzzz", -1, 4) = IndexOutOfBoundsException StringUtils.overlayString("abcdef", "zzzz", 2, 8) = IndexOutOfBoundsException
  
  Parameters:
  
  text - the String to do overlaying in, may be null
  
  overlay - the String to overlay, may be null
  
  start - the position to start overlaying at, must be valid
  
  end - the position to stop overlaying before, must be valid
  
  Returns:
  
  overlayed String, null if null String input
  
  Throws:
  
  NullPointerException - if text or overlay is null
  
  IndexOutOfBoundsException - if either position is invalid
- overlay
  public static String overlay(String str, String overlay, int start, int end)
  
  Overlays part of a String with another String.
  
  A null string input returns null. A negative index is treated as zero. An index greater than the string length is treated as the string length. The start index is always the smaller of the two indices.
  
  StringUtils.overlay(null, *, *, *) = null StringUtils.overlay("", "abc", 0, 0) = "abc" StringUtils.overlay("abcdef", null, 2, 4) = "abef" StringUtils.overlay("abcdef", "", 2, 4) = "abef" StringUtils.overlay("abcdef", "", 4, 2) = "abef" StringUtils.overlay("abcdef", "zzzz", 2, 4) = "abzzzzef" StringUtils.overlay("abcdef", "zzzz", 4, 2) = "abzzzzef" StringUtils.overlay("abcdef", "zzzz", -1, 4) = "zzzzef" StringUtils.overlay("abcdef", "zzzz", 2, 8) = "abzzzz" StringUtils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef" StringUtils.overlay("abcdef", "zzzz", 8, 10) = "abcdefzzzz"
  
  Parameters:
  
  str - the String to do overlaying in, may be null
  
  overlay - the String to overlay, may be null
  
  start - the position to start overlaying at
  
  end - the position to stop overlaying before
  
  Returns:
  
  overlayed String, null if null String input
  
  Since:
  
  2.0
- chomp
  public static String chomp(String str)
  
  Removes one newline from end of a String if it's there, otherwise leave it alone. A newline is "\n", "\r", or "\r\n".
  
  NOTE: This method changed in 2.0. It now more closely matches Perl chomp.
  
  StringUtils.chomp(null) = null StringUtils.chomp("") = "" StringUtils.chomp("abc \r") = "abc " StringUtils.chomp("abc\n") = "abc" StringUtils.chomp("abc\r\n") = "abc" StringUtils.chomp("abc\r\n\r\n") = "abc\r\n" StringUtils.chomp("abc\n\r") = "abc\n" StringUtils.chomp("abc\n\rabc") = "abc\n\rabc" StringUtils.chomp("\r") = "" StringUtils.chomp("\n") = "" StringUtils.chomp("\r\n") = ""
  
  Parameters:
  
  str - the String to chomp a newline from, may be null
  
  Returns:
  
  String without newline, null if null String input
- chomp
  public static String chomp(String str, String separator)
  
  Removes separator from the end of str if it's there, otherwise leave it alone.
  
  NOTE: This method changed in version 2.0. It now more closely matches Perl chomp. For the previous behavior, use substringBeforeLast(String, String). This method uses String.endsWith(String).
  
  StringUtils.chomp(null, *) = null StringUtils.chomp("", *) = "" StringUtils.chomp("foobar", "bar") = "foo" StringUtils.chomp("foobar", "baz") = "foobar" StringUtils.chomp("foo", "foo") = "" StringUtils.chomp("foo ", "foo") = "foo " StringUtils.chomp(" foo", "foo") = " " StringUtils.chomp("foo", "foooo") = "foo" StringUtils.chomp("foo", "") = "foo" StringUtils.chomp("foo", null) = "foo"
  
  Parameters:
  
  str - the String to chomp from, may be null
  
  separator - separator String, may be null
  
  Returns:
  
  String without trailing separator, null if null String input
- chompLast
  
  public static String chompLast(String str)
  
  Deprecated.
  Use chomp(String) instead. Method will be removed in Commons Lang 3.0.
  
  Remove any "\n" if and only if it is at the end of the supplied String.
  
  Parameters:
  
  str - the String to chomp from, must not be null
  
  Returns:
  
  String without chomped ending
  
  Throws:
  
  NullPointerException - if str is null
- chompLast
  
  public static String chompLast(String str, String sep)
  
  Deprecated.
  Use chomp(String,String) instead. Method will be removed in Commons Lang 3.0.
  
  Remove a value if and only if the String ends with that value.
  
  Parameters:
  
  str - the String to chomp from, must not be null
  
  sep - the String to chomp, must not be null
  
  Returns:
  
  String without chomped ending
  
  Throws:
  
  NullPointerException - if str or sep is null
- getChomp
  
  public static String getChomp(String str, String sep)
  
  Deprecated.
  Use substringAfterLast(String, String) instead (although this doesn't include the separator) Method will be removed in Commons Lang 3.0.
  
  Remove everything and return the last value of a supplied String, and everything after it from a String.
  
  Parameters:
  
  str - the String to chomp from, must not be null
  
  sep - the String to chomp, must not be null
  
  Returns:
  
  String chomped
  
  Throws:
  
  NullPointerException - if str or sep is null
- prechomp
  
  public static String prechomp(String str, String sep)
  
  Deprecated.
  Use substringAfter(String,String) instead. Method will be removed in Commons Lang 3.0.
  
  Remove the first value of a supplied String, and everything before it from a String.
  
  Parameters:
  
  str - the String to chomp from, must not be null
  
  sep - the String to chomp, must not be null
  
  Returns:
  
  String without chomped beginning
  
  Throws:
  
  NullPointerException - if str or sep is null
- getPrechomp
  
  public static String getPrechomp(String str, String sep)
  
  Deprecated.
  Use substringBefore(String,String) instead (although this doesn't include the separator). Method will be removed in Commons Lang 3.0.
  
  Remove and return everything before the first value of a supplied String from another String.
  
  Parameters:
  
  str - the String to chomp from, must not be null
  
  sep - the String to chomp, must not be null
  
  Returns:
  
  String prechomped
  
  Throws:
  
  NullPointerException - if str or sep is null
- chop
  public static String chop(String str)
  
  Remove the last character from a String.
  
  If the String ends in \r\n, then remove both of them.
  
  StringUtils.chop(null) = null StringUtils.chop("") = "" StringUtils.chop("abc \r") = "abc " StringUtils.chop("abc\n") = "abc" StringUtils.chop("abc\r\n") = "abc" StringUtils.chop("abc") = "ab" StringUtils.chop("abc\nabc") = "abc\nab" StringUtils.chop("a") = "" StringUtils.chop("\r") = "" StringUtils.chop("\n") = "" StringUtils.chop("\r\n") = ""
  
  Parameters:
  
  str - the String to chop last character from, may be null
  
  Returns:
  
  String without last character, null if null String input
- chopNewline
  
  public static String chopNewline(String str)
  
  Deprecated.
  Use chomp(String) instead. Method will be removed in Commons Lang 3.0.
  
  Removes \n from end of a String if it's there. If a \r precedes it, then remove that too.
  
  Parameters:
  
  str - the String to chop a newline from, must not be null
  
  Returns:
  
  String without newline
  
  Throws:
  
  NullPointerException - if str is null
- escape
  public static String escape(String str)
  
  Deprecated.
  Use StringEscapeUtils.escapeJava(String) This method will be removed in Commons Lang 3.0
  
  Escapes any values it finds into their String form.
  
  So a tab becomes the characters '\\' and 't'.
  
  As of Lang 2.0, this calls StringEscapeUtils.escapeJava(String) behind the scenes.
  
  Parameters:
  
  str - String to escape values in
  
  Returns:
  
  String with escaped values
  
  Throws:
  
  NullPointerException - if str is null
  
  See Also:
  
  StringEscapeUtils.escapeJava(String)
- repeat
  public static String repeat(String str, int repeat)
  
  Repeat a String repeat times to form a new String.
  
  StringUtils.repeat(null, 2) = null StringUtils.repeat("", 0) = "" StringUtils.repeat("", 2) = "" StringUtils.repeat("a", 3) = "aaa" StringUtils.repeat("ab", 2) = "abab" StringUtils.repeat("a", -2) = ""
  
  Parameters:
  
  str - the String to repeat, may be null
  
  repeat - number of times to repeat str, negative treated as zero
  
  Returns:
  
  a new String consisting of the original String repeated, null if null String input
- repeat
  public static String repeat(String str, String separator, int repeat)
  
  Repeat a String repeat times to form a new String, with a String separator injected each time.
  
  StringUtils.repeat(null, null, 2) = null StringUtils.repeat(null, "x", 2) = null StringUtils.repeat("", null, 0) = "" StringUtils.repeat("", "", 2) = "" StringUtils.repeat("", "x", 3) = "xxx" StringUtils.repeat("?", ", ", 3) = "?, ?, ?"
  
  Parameters:
  
  str - the String to repeat, may be null
  
  separator - the String to inject, may be null
  
  repeat - number of times to repeat str, negative treated as zero
  
  Returns:
  
  a new String consisting of the original String repeated, null if null String input
  
  Since:
  
  2.5
- rightPad
  public static String rightPad(String str, int size)
  
  Right pad a String with spaces (' ').
  
  The String is padded to the size of size.
  
  StringUtils.rightPad(null, *) = null StringUtils.rightPad("", 3) = " " StringUtils.rightPad("bat", 3) = "bat" StringUtils.rightPad("bat", 5) = "bat " StringUtils.rightPad("bat", 1) = "bat" StringUtils.rightPad("bat", -1) = "bat"
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  Returns:
  
  right padded String or original String if no padding is necessary, null if null String input
- rightPad
  public static String rightPad(String str, int size, char padChar)
  
  Right pad a String with a specified character.
  
  The String is padded to the size of size.
  
  StringUtils.rightPad(null, *, *) = null StringUtils.rightPad("", 3, 'z') = "zzz" StringUtils.rightPad("bat", 3, 'z') = "bat" StringUtils.rightPad("bat", 5, 'z') = "batzz" StringUtils.rightPad("bat", 1, 'z') = "bat" StringUtils.rightPad("bat", -1, 'z') = "bat"
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  padChar - the character to pad with
  
  Returns:
  
  right padded String or original String if no padding is necessary, null if null String input
  
  Since:
  
  2.0
- rightPad
  public static String rightPad(String str, int size, String padStr)
  
  Right pad a String with a specified String.
  
  The String is padded to the size of size.
  
  StringUtils.rightPad(null, *, *) = null StringUtils.rightPad("", 3, "z") = "zzz" StringUtils.rightPad("bat", 3, "yz") = "bat" StringUtils.rightPad("bat", 5, "yz") = "batyz" StringUtils.rightPad("bat", 8, "yz") = "batyzyzy" StringUtils.rightPad("bat", 1, "yz") = "bat" StringUtils.rightPad("bat", -1, "yz") = "bat" StringUtils.rightPad("bat", 5, null) = "bat " StringUtils.rightPad("bat", 5, "") = "bat "
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  padStr - the String to pad with, null or empty treated as single space
  
  Returns:
  
  right padded String or original String if no padding is necessary, null if null String input
- leftPad
  public static String leftPad(String str, int size)
  
  Left pad a String with spaces (' ').
  
  The String is padded to the size of size.
  
  StringUtils.leftPad(null, *) = null StringUtils.leftPad("", 3) = " " StringUtils.leftPad("bat", 3) = "bat" StringUtils.leftPad("bat", 5) = " bat" StringUtils.leftPad("bat", 1) = "bat" StringUtils.leftPad("bat", -1) = "bat"
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  Returns:
  
  left padded String or original String if no padding is necessary, null if null String input
- leftPad
  public static String leftPad(String str, int size, char padChar)
  
  Left pad a String with a specified character.
  
  Pad to a size of size.
  
  StringUtils.leftPad(null, *, *) = null StringUtils.leftPad("", 3, 'z') = "zzz" StringUtils.leftPad("bat", 3, 'z') = "bat" StringUtils.leftPad("bat", 5, 'z') = "zzbat" StringUtils.leftPad("bat", 1, 'z') = "bat" StringUtils.leftPad("bat", -1, 'z') = "bat"
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  padChar - the character to pad with
  
  Returns:
  
  left padded String or original String if no padding is necessary, null if null String input
  
  Since:
  
  2.0
- leftPad
  public static String leftPad(String str, int size, String padStr)
  
  Left pad a String with a specified String.
  
  Pad to a size of size.
  
  StringUtils.leftPad(null, *, *) = null StringUtils.leftPad("", 3, "z") = "zzz" StringUtils.leftPad("bat", 3, "yz") = "bat" StringUtils.leftPad("bat", 5, "yz") = "yzbat" StringUtils.leftPad("bat", 8, "yz") = "yzyzybat" StringUtils.leftPad("bat", 1, "yz") = "bat" StringUtils.leftPad("bat", -1, "yz") = "bat" StringUtils.leftPad("bat", 5, null) = " bat" StringUtils.leftPad("bat", 5, "") = " bat"
  
  Parameters:
  
  str - the String to pad out, may be null
  
  size - the size to pad to
  
  padStr - the String to pad with, null or empty treated as single space
  
  Returns:
  
  left padded String or original String if no padding is necessary, null if null String input
- length
  
  public static int length(String str)
  
  Gets a String's length or 0 if the String is null.
  
  Parameters:
  
  str - a String or null
  
  Returns:
  
  String length or 0 if the String is null.
  
  Since:
  
  2.4
- center
  public static String center(String str, int size)
  
  Centers a String in a larger String of size size using the space character (' ').
  If the size is less than the String length, the String is returned. A null String returns null. A negative size is treated as zero.
  
  Equivalent to center(str, size, " ").
  
  StringUtils.center(null, *) = null StringUtils.center("", 4) = " " StringUtils.center("ab", -1) = "ab" StringUtils.center("ab", 4) = " ab " StringUtils.center("abcd", 2) = "abcd" StringUtils.center("a", 4) = " a "
  
  Parameters:
  
  str - the String to center, may be null
  
  size - the int size of new String, negative treated as zero
  
  Returns:
  
  centered String, null if null String input
- center
  public static String center(String str, int size, char padChar)
  
  Centers a String in a larger String of size size. Uses a supplied character as the value to pad the String with.
  
  If the size is less than the String length, the String is returned. A null String returns null. A negative size is treated as zero.
  
  StringUtils.center(null, *, *) = null StringUtils.center("", 4, ' ') = " " StringUtils.center("ab", -1, ' ') = "ab" StringUtils.center("ab", 4, ' ') = " ab" StringUtils.center("abcd", 2, ' ') = "abcd" StringUtils.center("a", 4, ' ') = " a " StringUtils.center("a", 4, 'y') = "yayy"
  
  Parameters:
  
  str - the String to center, may be null
  
  size - the int size of new String, negative treated as zero
  
  padChar - the character to pad the new String with
  
  Returns:
  
  centered String, null if null String input
  
  Since:
  
  2.0
- center
  public static String center(String str, int size, String padStr)
  
  Centers a String in a larger String of size size. Uses a supplied String as the value to pad the String with.
  
  If the size is less than the String length, the String is returned. A null String returns null. A negative size is treated as zero.
  
  StringUtils.center(null, *, *) = null StringUtils.center("", 4, " ") = " " StringUtils.center("ab", -1, " ") = "ab" StringUtils.center("ab", 4, " ") = " ab" StringUtils.center("abcd", 2, " ") = "abcd" StringUtils.center("a", 4, " ") = " a " StringUtils.center("a", 4, "yz") = "yayz" StringUtils.center("abc", 7, null) = " abc " StringUtils.center("abc", 7, "") = " abc "
  
  Parameters:
  
  str - the String to center, may be null
  
  size - the int size of new String, negative treated as zero
  
  padStr - the String to pad the new String with, must not be null or empty
  
  Returns:
  
  centered String, null if null String input
  
  Throws:
  
  IllegalArgumentException - if padStr is null or empty
- upperCase
  public static String upperCase(String str)
  
  Converts a String to upper case as per String.toUpperCase().
  
  A null input String returns null.
  
  StringUtils.upperCase(null) = null StringUtils.upperCase("") = "" StringUtils.upperCase("aBc") = "ABC"
  
  Note: As described in the documentation for String.toUpperCase(), the result of this method is affected by the current locale. For platform-independent case transformations, the method lowerCase(String, Locale) should be used with a specific locale (e.g. Locale.ENGLISH).
  
  Parameters:
  
  str - the String to upper case, may be null
  
  Returns:
  
  the upper cased String, null if null String input
- upperCase
  public static String upperCase(String str, Locale locale)
  
  Converts a String to upper case as per String.toUpperCase(Locale).
  
  A null input String returns null.
  
  StringUtils.upperCase(null, Locale.ENGLISH) = null StringUtils.upperCase("", Locale.ENGLISH) = "" StringUtils.upperCase("aBc", Locale.ENGLISH) = "ABC"
  
  Parameters:
  
  str - the String to upper case, may be null
  
  locale - the locale that defines the case transformation rules, must not be null
  
  Returns:
  
  the upper cased String, null if null String input
  
  Since:
  
  2.5
- lowerCase
  public static String lowerCase(String str)
  
  Converts a String to lower case as per String.toLowerCase().
  
  A null input String returns null.
  
  StringUtils.lowerCase(null) = null StringUtils.lowerCase("") = "" StringUtils.lowerCase("aBc") = "abc"
  
  Note: As described in the documentation for String.toLowerCase(), the result of this method is affected by the current locale. For platform-independent case transformations, the method lowerCase(String, Locale) should be used with a specific locale (e.g. Locale.ENGLISH).
  
  Parameters:
  
  str - the String to lower case, may be null
  
  Returns:
  
  the lower cased String, null if null String input
- lowerCase
  public static String lowerCase(String str, Locale locale)
  
  Converts a String to lower case as per String.toLowerCase(Locale).
  
  A null input String returns null.
  
  StringUtils.lowerCase(null, Locale.ENGLISH) = null StringUtils.lowerCase("", Locale.ENGLISH) = "" StringUtils.lowerCase("aBc", Locale.ENGLISH) = "abc"
  
  Parameters:
  
  str - the String to lower case, may be null
  
  locale - the locale that defines the case transformation rules, must not be null
  
  Returns:
  
  the lower cased String, null if null String input
  
  Since:
  
  2.5
- capitalize
  public static String capitalize(String str)
  
  Capitalizes a String changing the first letter to title case as per Character.toTitleCase(char). No other letters are changed.
  
  For a word based algorithm, see WordUtils.capitalize(String). A null input String returns null.
  
  StringUtils.capitalize(null) = null StringUtils.capitalize("") = "" StringUtils.capitalize("cat") = "Cat" StringUtils.capitalize("cAt") = "CAt"
  
  Parameters:
  
  str - the String to capitalize, may be null
  
  Returns:
  
  the capitalized String, null if null String input
  
  Since:
  
  2.0
  
  See Also:
  
  WordUtils.capitalize(String)
  
  uncapitalize(String)
- capitalise
  
  public static String capitalise(String str)
  
  Deprecated.
  Use the standardly named capitalize(String). Method will be removed in Commons Lang 3.0.
  
  Capitalizes a String changing the first letter to title case as per Character.toTitleCase(char). No other letters are changed.
  
  Parameters:
  
  str - the String to capitalize, may be null
  
  Returns:
  
  the capitalized String, null if null String input
- uncapitalize
  public static String uncapitalize(String str)
  
  Uncapitalizes a String changing the first letter to title case as per Character.toLowerCase(char). No other letters are changed.
  
  For a word based algorithm, see WordUtils.uncapitalize(String). A null input String returns null.
  
  StringUtils.uncapitalize(null) = null StringUtils.uncapitalize("") = "" StringUtils.uncapitalize("Cat") = "cat" StringUtils.uncapitalize("CAT") = "cAT"
  
  Parameters:
  
  str - the String to uncapitalize, may be null
  
  Returns:
  
  the uncapitalized String, null if null String input
  
  Since:
  
  2.0
  
  See Also:
  
  WordUtils.uncapitalize(String)
  
  capitalize(String)
- uncapitalise
  
  public static String uncapitalise(String str)
  
  Deprecated.
  Use the standardly named uncapitalize(String). Method will be removed in Commons Lang 3.0.
  
  Uncapitalizes a String changing the first letter to title case as per Character.toLowerCase(char). No other letters are changed.
  
  Parameters:
  
  str - the String to uncapitalize, may be null
  
  Returns:
  
  the uncapitalized String, null if null String input
- swapCase
  public static String swapCase(String str)
  
  Swaps the case of a String changing upper and title case to lower case, and lower case to upper case.
  
  Upper case character converts to Lower case
  
  Title case character converts to Lower case
  
  Lower case character converts to Upper case
  
  For a word based algorithm, see WordUtils.swapCase(String). A null input String returns null.
  
  StringUtils.swapCase(null) = null StringUtils.swapCase("") = "" StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
  
  NOTE: This method changed in Lang version 2.0. It no longer performs a word based algorithm. If you only use ASCII, you will notice no change. That functionality is available in WordUtils.
  
  Parameters:
  
  str - the String to swap case, may be null
  
  Returns:
  
  the changed String, null if null String input
- capitaliseAllWords
  
  public static String capitaliseAllWords(String str)
  
  Deprecated.
  Use the relocated WordUtils.capitalize(String). Method will be removed in Commons Lang 3.0.
  
  Capitalizes all the whitespace separated words in a String. Only the first letter of each word is changed.
  
  Whitespace is defined by Character.isWhitespace(char). A null input String returns null.
  
  Parameters:
  
  str - the String to capitalize, may be null
  
  Returns:
  
  capitalized String, null if null String input
- countMatches
  public static int countMatches(String str, String sub)
  
  Counts how many times the substring appears in the larger String.
  
  A null or empty ("") String input returns 0.
  
  StringUtils.countMatches(null, *) = 0 StringUtils.countMatches("", *) = 0 StringUtils.countMatches("abba", null) = 0 StringUtils.countMatches("abba", "") = 0 StringUtils.countMatches("abba", "a") = 2 StringUtils.countMatches("abba", "ab") = 1 StringUtils.countMatches("abba", "xxx") = 0
  
  Parameters:
  
  str - the String to check, may be null
  
  sub - the substring to count, may be null
  
  Returns:
  
  the number of occurrences, 0 if either String is null
- isAlpha
  public static boolean isAlpha(String str)
  
  Checks if the String contains only unicode letters.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isAlpha(null) = false StringUtils.isAlpha("") = true StringUtils.isAlpha(" ") = false StringUtils.isAlpha("abc") = true StringUtils.isAlpha("ab2c") = false StringUtils.isAlpha("ab-c") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains letters, and is non-null
- isAlphaSpace
  public static boolean isAlphaSpace(String str)
  
  Checks if the String contains only unicode letters and space (' ').
  
  null will return false An empty String (length()=0) will return true.
  
  StringUtils.isAlphaSpace(null) = false StringUtils.isAlphaSpace("") = true StringUtils.isAlphaSpace(" ") = true StringUtils.isAlphaSpace("abc") = true StringUtils.isAlphaSpace("ab c") = true StringUtils.isAlphaSpace("ab2c") = false StringUtils.isAlphaSpace("ab-c") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains letters and space, and is non-null
- isAlphanumeric
  public static boolean isAlphanumeric(String str)
  
  Checks if the String contains only unicode letters or digits.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isAlphanumeric(null) = false StringUtils.isAlphanumeric("") = true StringUtils.isAlphanumeric(" ") = false StringUtils.isAlphanumeric("abc") = true StringUtils.isAlphanumeric("ab c") = false StringUtils.isAlphanumeric("ab2c") = true StringUtils.isAlphanumeric("ab-c") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains letters or digits, and is non-null
- isAlphanumericSpace
  public static boolean isAlphanumericSpace(String str)
  
  Checks if the String contains only unicode letters, digits or space (' ').
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isAlphanumeric(null) = false StringUtils.isAlphanumeric("") = true StringUtils.isAlphanumeric(" ") = true StringUtils.isAlphanumeric("abc") = true StringUtils.isAlphanumeric("ab c") = true StringUtils.isAlphanumeric("ab2c") = true StringUtils.isAlphanumeric("ab-c") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains letters, digits or space, and is non-null
- isAsciiPrintable
  public static boolean isAsciiPrintable(String str)
  
  Checks if the string contains only ASCII printable characters.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isAsciiPrintable(null) = false StringUtils.isAsciiPrintable("") = true StringUtils.isAsciiPrintable(" ") = true StringUtils.isAsciiPrintable("Ceki") = true StringUtils.isAsciiPrintable("ab2c") = true StringUtils.isAsciiPrintable("!ab-c~") = true StringUtils.isAsciiPrintable(" ") = true StringUtils.isAsciiPrintable("!") = true StringUtils.isAsciiPrintable("~") = true StringUtils.isAsciiPrintable("") = false StringUtils.isAsciiPrintable("Ceki Gülcü") = false
  
  Parameters:
  
  str - the string to check, may be null
  
  Returns:
  
  true if every character is in the range 32 thru 126
  
  Since:
  
  2.1
- isNumeric
  public static boolean isNumeric(String str)
  
  Checks if the String contains only unicode digits. A decimal point is not a unicode digit and returns false.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isNumeric(null) = false StringUtils.isNumeric("") = true StringUtils.isNumeric(" ") = false StringUtils.isNumeric("123") = true StringUtils.isNumeric("12 3") = false StringUtils.isNumeric("ab2c") = false StringUtils.isNumeric("12-3") = false StringUtils.isNumeric("12.3") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains digits, and is non-null
- isNumericSpace
  public static boolean isNumericSpace(String str)
  
  Checks if the String contains only unicode digits or space (' '). A decimal point is not a unicode digit and returns false.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isNumeric(null) = false StringUtils.isNumeric("") = true StringUtils.isNumeric(" ") = true StringUtils.isNumeric("123") = true StringUtils.isNumeric("12 3") = true StringUtils.isNumeric("ab2c") = false StringUtils.isNumeric("12-3") = false StringUtils.isNumeric("12.3") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains digits or space, and is non-null
- isWhitespace
  public static boolean isWhitespace(String str)
  
  Checks if the String contains only whitespace.
  
  null will return false. An empty String (length()=0) will return true.
  
  StringUtils.isWhitespace(null) = false StringUtils.isWhitespace("") = true StringUtils.isWhitespace(" ") = true StringUtils.isWhitespace("abc") = false StringUtils.isWhitespace("ab2c") = false StringUtils.isWhitespace("ab-c") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains whitespace, and is non-null
  
  Since:
  
  2.0
- isAllLowerCase
  public static boolean isAllLowerCase(String str)
  
  Checks if the String contains only lowercase characters.
  
  null will return false. An empty String (length()=0) will return false.
  
  StringUtils.isAllLowerCase(null) = false StringUtils.isAllLowerCase("") = false StringUtils.isAllLowerCase(" ") = false StringUtils.isAllLowerCase("abc") = true StringUtils.isAllLowerCase("abC") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains lowercase characters, and is non-null
  
  Since:
  
  2.5
- isAllUpperCase
  public static boolean isAllUpperCase(String str)
  
  Checks if the String contains only uppercase characters.
  
  null will return false. An empty String (length()=0) will return false.
  
  StringUtils.isAllUpperCase(null) = false StringUtils.isAllUpperCase("") = false StringUtils.isAllUpperCase(" ") = false StringUtils.isAllUpperCase("ABC") = true StringUtils.isAllUpperCase("aBC") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  true if only contains uppercase characters, and is non-null
  
  Since:
  
  2.5
- defaultString
  public static String defaultString(String str)
  
  Returns either the passed in String, or if the String is null, an empty String ("").
  
  StringUtils.defaultString(null) = "" StringUtils.defaultString("") = "" StringUtils.defaultString("bat") = "bat"
  
  Parameters:
  
  str - the String to check, may be null
  
  Returns:
  
  the passed in String, or the empty String if it was null
  
  See Also:
  
  ObjectUtils.toString(Object)
  
  String.valueOf(Object)
- defaultString
  public static String defaultString(String str, String defaultStr)
  
  Returns either the passed in String, or if the String is null, the value of defaultStr.
  
  StringUtils.defaultString(null, "NULL") = "NULL" StringUtils.defaultString("", "NULL") = "" StringUtils.defaultString("bat", "NULL") = "bat"
  
  Parameters:
  
  str - the String to check, may be null
  
  defaultStr - the default String to return if the input is null, may be null
  
  Returns:
  
  the passed in String, or the default if it was null
  
  See Also:
  
  ObjectUtils.toString(Object,String)
  
  String.valueOf(Object)
- defaultIfBlank
  public static String defaultIfBlank(String str, String defaultStr)
  
  Returns either the passed in String, or if the String is whitespace, empty ("") or null, the value of defaultStr.
  
  StringUtils.defaultIfBlank(null, "NULL") = "NULL" StringUtils.defaultIfBlank("", "NULL") = "NULL" StringUtils.defaultIfBlank(" ", "NULL") = "NULL" StringUtils.defaultIfBlank("bat", "NULL") = "bat" StringUtils.defaultIfBlank("", null) = null
  
  Parameters:
  
  str - the String to check, may be null
  
  defaultStr - the default String to return if the input is whitespace, empty ("") or null, may be null
  
  Returns:
  
  the passed in String, or the default
  
  Since:
  
  2.6
  
  See Also:
  
  defaultString(String, String)
- defaultIfEmpty
  public static String defaultIfEmpty(String str, String defaultStr)
  
  Returns either the passed in String, or if the String is empty or null, the value of defaultStr.
  
  StringUtils.defaultIfEmpty(null, "NULL") = "NULL" StringUtils.defaultIfEmpty("", "NULL") = "NULL" StringUtils.defaultIfEmpty("bat", "NULL") = "bat" StringUtils.defaultIfEmpty("", null) = null
  
  Parameters:
  
  str - the String to check, may be null
  
  defaultStr - the default String to return if the input is empty ("") or null, may be null
  
  Returns:
  
  the passed in String, or the default
  
  See Also:
  
  defaultString(String, String)
- reverse
  public static String reverse(String str)
  
  Reverses a String as per StrBuilder.reverse().
  
  A null String returns null.
  
  StringUtils.reverse(null) = null StringUtils.reverse("") = "" StringUtils.reverse("bat") = "tab"
  
  Parameters:
  
  str - the String to reverse, may be null
  
  Returns:
  
  the reversed String, null if null String input
- reverseDelimited
  public static String reverseDelimited(String str, char separatorChar)
  
  Reverses a String that is delimited by a specific character.
  
  The Strings between the delimiters are not reversed. Thus java.lang.String becomes String.lang.java (if the delimiter is '.').
  
  StringUtils.reverseDelimited(null, *) = null StringUtils.reverseDelimited("", *) = "" StringUtils.reverseDelimited("a.b.c", 'x') = "a.b.c" StringUtils.reverseDelimited("a.b.c", ".") = "c.b.a"
  
  Parameters:
  
  str - the String to reverse, may be null
  
  separatorChar - the separator character to use
  
  Returns:
  
  the reversed String, null if null String input
  
  Since:
  
  2.0
- reverseDelimitedString
  public static String reverseDelimitedString(String str, String separatorChars)
  
  Deprecated.
  Use reverseDelimited(String, char) instead. This method is broken as the join doesn't know which char to use. Method will be removed in Commons Lang 3.0.
  
  Reverses a String that is delimited by a specific character.
  
  The Strings between the delimiters are not reversed. Thus java.lang.String becomes String.lang.java (if the delimiter is ".").
  
  StringUtils.reverseDelimitedString(null, *) = null StringUtils.reverseDelimitedString("",*) = "" StringUtils.reverseDelimitedString("a.b.c", null) = "a.b.c" StringUtils.reverseDelimitedString("a.b.c", ".") = "c.b.a"
  
  Parameters:
  
  str - the String to reverse, may be null
  
  separatorChars - the separator characters to use, null treated as whitespace
  
  Returns:
  
  the reversed String, null if null String input
- abbreviate
  public static String abbreviate(String str, int maxWidth)
  
  Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "Now is the time for..."
  
  Specifically:
  
  If str is less than maxWidth characters long, return it.
  
  Else abbreviate it to (substring(str, 0, max-3) + "...").
  
  If maxWidth is less than 4, throw an IllegalArgumentException.
  
  In no case will it return a String of length greater than maxWidth.
  
  StringUtils.abbreviate(null, *) = null StringUtils.abbreviate("", 4) = "" StringUtils.abbreviate("abcdefg", 6) = "abc..." StringUtils.abbreviate("abcdefg", 7) = "abcdefg" StringUtils.abbreviate("abcdefg", 8) = "abcdefg" StringUtils.abbreviate("abcdefg", 4) = "a..." StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException
  
  Parameters:
  
  str - the String to check, may be null
  
  maxWidth - maximum length of result String, must be at least 4
  
  Returns:
  
  abbreviated String, null if null String input
  
  Throws:
  
  IllegalArgumentException - if the width is too small
  
  Since:
  
  2.0
- abbreviate
  public static String abbreviate(String str, int offset, int maxWidth)
  
  Abbreviates a String using ellipses. This will turn "Now is the time for all good men" into "...is the time for..."
  
  Works like abbreviate(String, int), but allows you to specify a "left edge" offset. Note that this left edge is not necessarily going to be the leftmost character in the result, or the first character following the ellipses, but it will appear somewhere in the result.
  In no case will it return a String of length greater than maxWidth.
  
  StringUtils.abbreviate(null, *, *) = null StringUtils.abbreviate("", 0, 4) = "" StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 0, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 1, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 4, 10) = "abcdefg..." StringUtils.abbreviate("abcdefghijklmno", 5, 10) = "...fghi..." StringUtils.abbreviate("abcdefghijklmno", 6, 10) = "...ghij..." StringUtils.abbreviate("abcdefghijklmno", 8, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno" StringUtils.abbreviate("abcdefghij", 0, 3) = IllegalArgumentException StringUtils.abbreviate("abcdefghij", 5, 6) = IllegalArgumentException
  
  Parameters:
  
  str - the String to check, may be null
  
  offset - left edge of source String
  
  maxWidth - maximum length of result String, must be at least 4
  
  Returns:
  
  abbreviated String, null if null String input
  
  Throws:
  
  IllegalArgumentException - if the width is too small
  
  Since:
  
  2.0
- abbreviateMiddle
  public static String abbreviateMiddle(String str, String middle, int length)
  
  Abbreviates a String to the length passed, replacing the middle characters with the supplied replacement String.
  
  This abbreviation only occurs if the following criteria is met:
  
  Neither the String for abbreviation nor the replacement String are null or empty
  
  The length to truncate to is less than the length of the supplied String
  
  The length to truncate to is greater than 0
  
  The abbreviated String will have enough room for the length supplied replacement String and the first and last characters of the supplied String for abbreviation
  
  Otherwise, the returned String will be the same as the supplied String for abbreviation.
  StringUtils.abbreviateMiddle(null, null, 0) = null StringUtils.abbreviateMiddle("abc", null, 0) = "abc" StringUtils.abbreviateMiddle("abc", ".", 0) = "abc" StringUtils.abbreviateMiddle("abc", ".", 3) = "abc" StringUtils.abbreviateMiddle("abcdef", ".", 4) = "ab.f"
  
  Parameters:
  
  str - the String to abbreviate, may be null
  
  middle - the String to replace the middle characters with, may be null
  
  length - the length to abbreviate str to.
  
  Returns:
  
  the abbreviated String if the above criteria is met, or the original String supplied for abbreviation.
  
  Since:
  
  2.5
- difference
  public static String difference(String str1, String str2)
  
  Compares two Strings, and returns the portion where they differ. (More precisely, return the remainder of the second String, starting from where it's different from the first.)
  
  For example, difference("i am a machine", "i am a robot") -> "robot".
  
  StringUtils.difference(null, null) = null StringUtils.difference("", "") = "" StringUtils.difference("", "abc") = "abc" StringUtils.difference("abc", "") = "" StringUtils.difference("abc", "abc") = "" StringUtils.difference("ab", "abxyz") = "xyz" StringUtils.difference("abcde", "abxyz") = "xyz" StringUtils.difference("abcde", "xyz") = "xyz"
  
  Parameters:
  
  str1 - the first String, may be null
  
  str2 - the second String, may be null
  
  Returns:
  
  the portion of str2 where it differs from str1; returns the empty String if they are equal
  
  Since:
  
  2.0
- indexOfDifference
  public static int indexOfDifference(String str1, String str2)
  
  Compares two Strings, and returns the index at which the Strings begin to differ.
  
  For example, indexOfDifference("i am a machine", "i am a robot") -> 7
  
  StringUtils.indexOfDifference(null, null) = -1 StringUtils.indexOfDifference("", "") = -1 StringUtils.indexOfDifference("", "abc") = 0 StringUtils.indexOfDifference("abc", "") = 0 StringUtils.indexOfDifference("abc", "abc") = -1 StringUtils.indexOfDifference("ab", "abxyz") = 2 StringUtils.indexOfDifference("abcde", "abxyz") = 2 StringUtils.indexOfDifference("abcde", "xyz") = 0
  
  Parameters:
  
  str1 - the first String, may be null
  
  str2 - the second String, may be null
  
  Returns:
  
  the index where str2 and str1 begin to differ; -1 if they are equal
  
  Since:
  
  2.0
- indexOfDifference
  public static int indexOfDifference(String[] strs)
  
  Compares all Strings in an array and returns the index at which the Strings begin to differ.
  
  For example, indexOfDifference(new String[] {"i am a machine", "i am a robot"}) -> 7
  
  StringUtils.indexOfDifference(null) = -1 StringUtils.indexOfDifference(new String[] {}) = -1 StringUtils.indexOfDifference(new String[] {"abc"}) = -1 StringUtils.indexOfDifference(new String[] {null, null}) = -1 StringUtils.indexOfDifference(new String[] {"", ""}) = -1 StringUtils.indexOfDifference(new String[] {"", null}) = 0 StringUtils.indexOfDifference(new String[] {"abc", null, null}) = 0 StringUtils.indexOfDifference(new String[] {null, null, "abc"}) = 0 StringUtils.indexOfDifference(new String[] {"", "abc"}) = 0 StringUtils.indexOfDifference(new String[] {"abc", ""}) = 0 StringUtils.indexOfDifference(new String[] {"abc", "abc"}) = -1 StringUtils.indexOfDifference(new String[] {"abc", "a"}) = 1 StringUtils.indexOfDifference(new String[] {"ab", "abxyz"}) = 2 StringUtils.indexOfDifference(new String[] {"abcde", "abxyz"}) = 2 StringUtils.indexOfDifference(new String[] {"abcde", "xyz"}) = 0 StringUtils.indexOfDifference(new String[] {"xyz", "abcde"}) = 0 StringUtils.indexOfDifference(new String[] {"i am a machine", "i am a robot"}) = 7
  
  Parameters:
  
  strs - array of strings, entries may be null
  
  Returns:
  
  the index where the strings begin to differ; -1 if they are all equal
  
  Since:
  
  2.4
- getCommonPrefix
  public static String getCommonPrefix(String[] strs)
  
  Compares all Strings in an array and returns the initial sequence of characters that is common to all of them.
  
  For example, getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) -> "i am a "
  
  StringUtils.getCommonPrefix(null) = "" StringUtils.getCommonPrefix(new String[] {}) = "" StringUtils.getCommonPrefix(new String[] {"abc"}) = "abc" StringUtils.getCommonPrefix(new String[] {null, null}) = "" StringUtils.getCommonPrefix(new String[] {"", ""}) = "" StringUtils.getCommonPrefix(new String[] {"", null}) = "" StringUtils.getCommonPrefix(new String[] {"abc", null, null}) = "" StringUtils.getCommonPrefix(new String[] {null, null, "abc"}) = "" StringUtils.getCommonPrefix(new String[] {"", "abc"}) = "" StringUtils.getCommonPrefix(new String[] {"abc", ""}) = "" StringUtils.getCommonPrefix(new String[] {"abc", "abc"}) = "abc" StringUtils.getCommonPrefix(new String[] {"abc", "a"}) = "a" StringUtils.getCommonPrefix(new String[] {"ab", "abxyz"}) = "ab" StringUtils.getCommonPrefix(new String[] {"abcde", "abxyz"}) = "ab" StringUtils.getCommonPrefix(new String[] {"abcde", "xyz"}) = "" StringUtils.getCommonPrefix(new String[] {"xyz", "abcde"}) = "" StringUtils.getCommonPrefix(new String[] {"i am a machine", "i am a robot"}) = "i am a "
  
  Parameters:
  
  strs - array of String objects, entries may be null
  
  Returns:
  
  the initial sequence of characters that are common to all Strings in the array; empty String if the array is null, the elements are all null or if there is no common prefix.
  
  Since:
  
  2.4
- getLevenshteinDistance
  public static int getLevenshteinDistance(String s, String t)
  
  Find the Levenshtein distance between two Strings.
  
  This is the number of changes needed to change one String into another, where each change is a single character modification (deletion, insertion or substitution).
  
  The previous implementation of the Levenshtein distance algorithm was from http://www.merriampark.com/ld.htm
  
  Chas Emerick has written an implementation in Java, which avoids an OutOfMemoryError which can occur when my Java implementation is used with very large strings.
  This implementation of the Levenshtein distance algorithm is from http://www.merriampark.com/ldjava.htm
  
  StringUtils.getLevenshteinDistance(null, *) = IllegalArgumentException StringUtils.getLevenshteinDistance(*, null) = IllegalArgumentException StringUtils.getLevenshteinDistance("","") = 0 StringUtils.getLevenshteinDistance("","a") = 1 StringUtils.getLevenshteinDistance("aaapppp", "") = 7 StringUtils.getLevenshteinDistance("frog", "fog") = 1 StringUtils.getLevenshteinDistance("fly", "ant") = 3 StringUtils.getLevenshteinDistance("elephant", "hippo") = 7 StringUtils.getLevenshteinDistance("hippo", "elephant") = 7 StringUtils.getLevenshteinDistance("hippo", "zzzzzzzz") = 8 StringUtils.getLevenshteinDistance("hello", "hallo") = 1
  
  Parameters:
  
  s - the first String, must not be null
  
  t - the second String, must not be null
  
  Returns:
  
  result distance
  
  Throws:
  
  IllegalArgumentException - if either String input null
- startsWith
  public static boolean startsWith(String str, String prefix)
  
  Check if a String starts with a specified prefix.
  
  nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.
  
  StringUtils.startsWith(null, null) = true StringUtils.startsWith(null, "abc") = false StringUtils.startsWith("abcdef", null) = false StringUtils.startsWith("abcdef", "abc") = true StringUtils.startsWith("ABCDEF", "abc") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  prefix - the prefix to find, may be null
  
  Returns:
  
  true if the String starts with the prefix, case sensitive, or both null
  
  Since:
  
  2.4
  
  See Also:
  
  String.startsWith(String)
- startsWithIgnoreCase
  public static boolean startsWithIgnoreCase(String str, String prefix)
  
  Case insensitive check if a String starts with a specified prefix.
  
  nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive.
  
  StringUtils.startsWithIgnoreCase(null, null) = true StringUtils.startsWithIgnoreCase(null, "abc") = false StringUtils.startsWithIgnoreCase("abcdef", null) = false StringUtils.startsWithIgnoreCase("abcdef", "abc") = true StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
  
  Parameters:
  
  str - the String to check, may be null
  
  prefix - the prefix to find, may be null
  
  Returns:
  
  true if the String starts with the prefix, case insensitive, or both null
  
  Since:
  
  2.4
  
  See Also:
  
  String.startsWith(String)
- startsWithAny
  public static boolean startsWithAny(String string, String[] searchStrings)
  
  Check if a String starts with any of an array of specified strings.
  
  StringUtils.startsWithAny(null, null) = false StringUtils.startsWithAny(null, new String[] {"abc"}) = false StringUtils.startsWithAny("abcxyz", null) = false StringUtils.startsWithAny("abcxyz", new String[] {""}) = false StringUtils.startsWithAny("abcxyz", new String[] {"abc"}) = true StringUtils.startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
  
  Parameters:
  
  string - the String to check, may be null
  
  searchStrings - the Strings to find, may be null or empty
  
  Returns:
  
  true if the String starts with any of the the prefixes, case insensitive, or both null
  
  Since:
  
  2.5
  
  See Also:
  
  startsWith(String, String)
- endsWith
  public static boolean endsWith(String str, String suffix)
  
  Check if a String ends with a specified suffix.
  
  nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.
  
  StringUtils.endsWith(null, null) = true StringUtils.endsWith(null, "def") = false StringUtils.endsWith("abcdef", null) = false StringUtils.endsWith("abcdef", "def") = true StringUtils.endsWith("ABCDEF", "def") = false StringUtils.endsWith("ABCDEF", "cde") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  suffix - the suffix to find, may be null
  
  Returns:
  
  true if the String ends with the suffix, case sensitive, or both null
  
  Since:
  
  2.4
  
  See Also:
  
  String.endsWith(String)
- endsWithIgnoreCase
  public static boolean endsWithIgnoreCase(String str, String suffix)
  
  Case insensitive check if a String ends with a specified suffix.
  
  nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive.
  
  StringUtils.endsWithIgnoreCase(null, null) = true StringUtils.endsWithIgnoreCase(null, "def") = false StringUtils.endsWithIgnoreCase("abcdef", null) = false StringUtils.endsWithIgnoreCase("abcdef", "def") = true StringUtils.endsWithIgnoreCase("ABCDEF", "def") = true StringUtils.endsWithIgnoreCase("ABCDEF", "cde") = false
  
  Parameters:
  
  str - the String to check, may be null
  
  suffix - the suffix to find, may be null
  
  Returns:
  
  true if the String ends with the suffix, case insensitive, or both null
  
  Since:
  
  2.4
  
  See Also:
  
  String.endsWith(String)
- normalizeSpace
  public static String normalizeSpace(String str)
  
  Similar to http://www.w3.org/TR/xpath/#function-normalize -space
  
  The function returns the argument string with whitespace normalized by using {@link #trim(String)} to remove leading and trailing whitespace and then replacing sequences of whitespace characters by a single space.
  In XML Whitespace characters are the same as those allowed by the S production, which is S ::= (#x20 | #x9 | #xD | #xA)+
  See Java's Character.isWhitespace(char) for which characters are considered whitespace.
  The difference is that Java's whitespace includes vertical tab and form feed, which this functional will also normalize. Additonally {@link #trim(String)} removes control characters (char <= 32) from both ends of this String.
  
  Parameters:
  
  str - the source String to normalize whitespaces from, may be null
  
  Returns:
  
  the modified string with whitespace normalized, null if null String input
  
  Since:
  
  2.6
  
  See Also:
  
  Character.isWhitespace(char)
  
  trim(String)
  
  http://www.w3.org/TR/xpath/#function-normalize-space
- endsWithAny
  public static boolean endsWithAny(String string, String[] searchStrings)
  
  Check if a String ends with any of an array of specified strings.
  
  StringUtils.endsWithAny(null, null) = false StringUtils.endsWithAny(null, new String[] {"abc"}) = false StringUtils.endsWithAny("abcxyz", null) = false StringUtils.endsWithAny("abcxyz", new String[] {""}) = true StringUtils.endsWithAny("abcxyz", new String[] {"xyz"}) = true StringUtils.endsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
  
  Parameters:
  
  string - the String to check, may be null
  
  searchStrings - the Strings to find, may be null or empty
  
  Returns:
  
  true if the String ends with any of the the prefixes, case insensitive, or both null
  
  Since:
  
  2.6

Class StringUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Details

EMPTY

INDEX_NOT_FOUND

Constructor Details

StringUtils

Method Details

isEmpty

isNotEmpty

isBlank

isNotBlank

clean

trim

trimToNull

trimToEmpty

strip

stripToNull

stripToEmpty

strip

stripStart

stripEnd

stripAll

stripAll

equals

equalsIgnoreCase

indexOf

indexOf

indexOf

ordinalIndexOf

indexOf

indexOfIgnoreCase

indexOfIgnoreCase

lastIndexOf

lastIndexOf

lastIndexOf

lastOrdinalIndexOf

lastIndexOf

lastIndexOfIgnoreCase

lastIndexOfIgnoreCase

contains

contains

containsIgnoreCase

indexOfAny

indexOfAny

containsAny

containsAny

indexOfAnyBut

indexOfAnyBut

containsOnly

containsOnly

containsNone

containsNone

indexOfAny

lastIndexOfAny

substring

substring

left

right

mid

substringBefore

substringAfter

substringBeforeLast

substringAfterLast

substringBetween

substringBetween

substringsBetween

getNestedString

getNestedString

split

split

split

split

splitByWholeSeparator

splitByWholeSeparator

splitByWholeSeparatorPreserveAllTokens

splitByWholeSeparatorPreserveAllTokens