StringHelper (Tentackle Common 8.2.6.0 API)

java.lang.Object
- org.tentackle.common.StringHelper

public final class StringHelper
extends Object

Some handy methods for strings.

Author:: harald

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`maxLogCollectionSize` Limit size of collection to be logged. If an object is logged and it is a collection and the size exceeds `maxLogCollectionSize`, only the number of items is logged in `objectToLoggableString(java.lang.Object)` instead of each item.
`static Function<String,String>`	`stringNormalizer` The default normalizer used within the application.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`blank(char[] buf)` Null-safe char array filler. Fills with blanks.
`static int`	`countOccurrences(String str, char c)` Counts the number of occurrences of a given character in a string.
`static String`	`digitToString(Character digit)` Gets the word-string for a digit. Example:
`static boolean`	`equalsIgnoreCase(String a, String b)` Null safe `String.equalsIgnoreCase(String)`.
`static void`	`fill(char[] buf, char val)` Null-safe char array filler.
`static String`	`fillLeft(String str, int length, char filler)` Fills up a string from the left with a filler character to match a given length. If the string is already longer, nothing happens.
`static String`	`fillRight(String str, int length, char filler)` Fills up a string to the right with a filler character to match a given length. If the string is already longer, nothing happens.
`static String`	`firstBefore(String str, char delimiter)` Gets the part of a string before a given delimiter.
`static String`	`firstLine(String str)` Gets the first line from a multi-line string.
`static String`	`firstToLower(String str)` Converts the first character of string to uppercase.
`static String`	`firstToUpper(String str)` Converts the first character of string to uppercase.
`static String`	`getContinuedLine(String line)` Checks whether given string introduces a continuation line.
`static String`	`getPlainClassName(String className)` Gets a classname without any optional generics.
`static String`	`hash(String algorithm, char[] salt, char[] input)` Builds a hash from an array of chars. Note that this method converts the characters to bytes via `toBytes(char[])` before applying the hash.
`static boolean`	`isAllDigits(String str)` checks if a string contains only digits, i.e.
`static boolean`	`isAllDigits(String str, boolean whitespaceAllowed)` Checks if a string contains only digits or whitespaces, i.e.
`static boolean`	`isAllWhitespace(String str)` Checks if string contains only whitespaces.
`static boolean`	`isReservedWord(String word)` Returns whether given string is a reserved java keyword.
`static boolean`	`isValidJavaClassName(String className)` Checks that given string is a valid Java classname. Both classnames with a full classpath or without are validated.
`static boolean`	`isValidJavaIdentifier(String str)` Returns whether the given string is a valid java identifier.
`static boolean`	`isValidJavaPackageName(String packageName)` Checks that given string is a valid Java packagename. This is very restrictive verification.
`static String`	`lastAfter(String str, char delimiter)` Gets the part of a string after a given delimiter.
`static String`	`normalize(String str)` Normalizes a string (phonetically) for use as PDO.normText using `stringNormalizer`.
`static String`	`normalize(String str, Function<String,String> normalizer)` Normalizes a string (phonetically) for use as PDO.normText.
`static String`	`objectArrayToString(Object[] objArray, String separator)` Creates a string from an object array.
`static String`	`objectToLoggableString(Object object)` Converts a value to a loggable string.
`static String`	`parseString(String str)` Parses a string. The string may be enclosed in double- or single quotes which will be removed.
`static String`	`readTextFromResource(String resourceName)` Reads a textfile from a resource. The textfile must be in the classpath.
`static String`	`removeTrailingText(String str, String trail)` Removes a trailing text from a string.
`static List<String>`	`split(String str, String delimiters)` Splits a string keeping strings together. The strings may be enclosed in double- or single quotes which will not be removed.
`static String`	`stripEnclosingDoubleQuotes(String str)` Strips enclosing double quotes.
`static String`	`toAsciiLetterOrDigit(String str)` Converts to string containing only the letters A-z or digits. All other characters will be converted to an underscore.
`static byte[]`	`toBytes(char c)` Converts a single (unicode) char to a byte-array.
`static byte[]`	`toBytes(char[] chars)` Converts a char-array to a byte-array.
`static char[]`	`toCharArray(String str)` Transforms a string to a char-array.
`static String`	`toDoubleQuotes(String str)` Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Unix rules.
`static String`	`toDTA(String str)` Filters illegal chars for DTA-Files (German "DATENAUSTAUSCH" banking format).
`static String`	`toFixedLength(String str, int length)` Takes a string and returns one with a given length, cutting or filling up with spaces, whatever appropriate.
`static String`	`toFixedLength(String str, int length, char filler)` Takes a string and returns one with a given length, cutting or filling up with fillchars, whatever appropriate.
`static String`	`toFixedLengthLeftFill(String str, int length)` Takes a string and returns one with a given length, cutting or filling up with spaces from the left, whatever appropriate.
`static String`	`toFixedLengthLeftFill(String str, int length, char filler)` Takes a string and returns one with a given length, cutting or filling up with fillchars from the left, whatever appropriate.
`static String`	`toHexString(byte[] binaryData)` Creates a human-readable hex-String out of a byte-array (e.g.
`static String`	`toHTML(String text)` Converts a multiline string to an HTML-string that can be displayed in a label.
`static String`	`toLower(String str)` Converts a string to lowercase allowing null values.
`static String`	`toParsableString(String str)` Converts a string to a string parsable by `parseString(java.lang.String)`.
`static String`	`toUpper(String str)` Converts a string to uppercase allowing null values.
`static String`	`toVarName(String str)` Filters illegal chars for Java variable names.
`static String`	`trim(String s)` Trims a string.
`static String`	`trim(String s, int max)` Trims a string.
`static String`	`trimLeft(String str, char filler)` Cuts leading characters.
`static String`	`trimRight(String str, char filler)` Cuts trailing characters.
`static String`	`unDiacrit(String str, boolean keepLength)` Converts special unicode characters (so-called diacrits) to standard ascii. Supports also special german and northern european "umlauts".

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

- Field Detail
  - maxLogCollectionSize
```
public static int maxLogCollectionSize
```
    Limit size of collection to be logged.
    If an object is logged and it is a collection and the size exceeds maxLogCollectionSize, only the number of items is logged in objectToLoggableString(java.lang.Object) instead of each item.
  - stringNormalizer
```
public static Function<String,String> stringNormalizer
```
    The default normalizer used within the application. Defaults to DefaultStringNormalizer.
- Method Detail
  - equalsIgnoreCase
```
public static boolean equalsIgnoreCase(String a,
                                       String b)
```
    Null safe String.equalsIgnoreCase(String).
    
    Parameters:
    
    a - first string, may be null
    
    b - second string, may be null
    
    Returns:
    
    true if equal ignoring the case or both are null
  - toUpper
```
public static String toUpper(String str)
```
    Converts a string to uppercase allowing null values.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the uppercase string or null
  - toLower
```
public static String toLower(String str)
```
    Converts a string to lowercase allowing null values.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the lowercase string or null
  - firstToUpper
```
public static String firstToUpper(String str)
```
    Converts the first character of string to uppercase.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the converted string
  - firstToLower
```
public static String firstToLower(String str)
```
    Converts the first character of string to uppercase.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the converted string
  - getPlainClassName
```
public static String getPlainClassName(String className)
```
    Gets a classname without any optional generics.
    
    Parameters:
    
    className - the original classname
    
    Returns:
    
    classname without generics
  - getContinuedLine
```
public static String getContinuedLine(String line)
```
    Checks whether given string introduces a continuation line.
    This is the case if the last character is an unquoted backslash.
    
    Parameters:
    
    line - the source line
    
    Returns:
    
    null if line does not introduce a continuation line
  - toDoubleQuotes
```
public static String toDoubleQuotes(String str)
```
    Takes a string, surrounds it with double-quotes and escapes all double-quotes already in the string according to Unix rules. Example:
```
 Length 5" --> "Length 5\""
 
```
    Parameters:
    
    str - the string
    
    Returns:
    
    the string in double quotes
  - parseString
```
public static String parseString(String str)
```
    Parses a string.
    The string may be enclosed in double- or single quotes which will be removed. Those special characters may be escaped by a backslash. The backslash itself can be written as a double backslash. Special escapes are:
    \n = new line \r = carriage return \t = tab \f = form feed
    
    Parameters:
    
    str - the source string
    
    Returns:
    
    a string, never null
  - toParsableString
```
public static String toParsableString(String str)
```
    Converts a string to a string parsable by parseString(java.lang.String).
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the parsable string
  - split
```
public static List<String> split(String str,
                                 String delimiters)
```
    Splits a string keeping strings together.
    The strings may be enclosed in double- or single quotes which will not be removed. Those special characters may be escaped by a backslash. The backslash itself can be written as a double backslash. Special escapes are:
    \n = new line \r = carriage return \t = tab \f = form feed
    
    Parameters:
    
    str - the string
    
    delimiters - the delimiter characters
    
    Returns:
    
    the strings, never null
  - isValidJavaClassName
```
public static boolean isValidJavaClassName(String className)
```
    Checks that given string is a valid Java classname.
    Both classnames with a full classpath or without are validated.
    
    Parameters:
    
    className - the classname
    
    Returns:
    
    true if valid
  - isValidJavaPackageName
```
public static boolean isValidJavaPackageName(String packageName)
```
    Checks that given string is a valid Java packagename.
    This is very restrictive verification. Packagenames must be all lowercase alphabetic or digits and must contain only dots and underscores.
    
    Parameters:
    
    packageName - the packagename
    
    Returns:
    
    true if valid
  - isValidJavaIdentifier
```
public static boolean isValidJavaIdentifier(String str)
```
    Returns whether the given string is a valid java identifier.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    true if valid, false if not
  - readTextFromResource
```
public static String readTextFromResource(String resourceName)
                                   throws IOException
```
    Reads a textfile from a resource.
    The textfile must be in the classpath.
    Example:
```
   String model = StringHelper.readTestFromResource("org/tentackle/model/TestModel.txt");
 
```
    Parameters:
    
    resourceName - the name of the resource
    
    Returns:
    
    the loaded text
    
    Throws:
    
    IOException - if loading failed or no such resource
  - isAllWhitespace
```
public static boolean isAllWhitespace(String str)
```
    Checks if string contains only whitespaces.
    
    Parameters:
    
    str - the string to check
    
    Returns:
    
    true if null, empty or all whitespace, false if at least one non-whitespace-character found
  - isReservedWord
```
public static boolean isReservedWord(String word)
```
    Returns whether given string is a reserved java keyword.
    
    Parameters:
    
    word - the string to test
    
    Returns:
    
    true if java reserved word
  - digitToString
```
public static String digitToString(Character digit)
```
    Gets the word-string for a digit.
    Example:
```
 '0' --> "zero"
 
```
    Parameters:
    
    digit - the digit character
    
    Returns:
    
    the word-string
  - unDiacrit
```
public static String unDiacrit(String str,
                               boolean keepLength)
```
    Converts special unicode characters (so-called diacrits) to standard ascii.
    Supports also special german and northern european "umlauts".
    
    Parameters:
    
    str - the string to be converted
    
    keepLength - true if the length should be kept, i.e. no Ä to AE, but to A
    
    Returns:
    
    the converted string
  - normalize
```
public static String normalize(String str,
                               Function<String,String> normalizer)
```
    Normalizes a string (phonetically) for use as PDO.normText.
    
    Parameters:
    
    str - the string to be normalized
    
    normalizer - the normalizer to use, null = global default
    
    Returns:
    
    the normalized string
  - normalize
```
public static String normalize(String str)
```
    Normalizes a string (phonetically) for use as PDO.normText using stringNormalizer.
    
    Parameters:
    
    str - the string to be normalized
    
    Returns:
    
    the normalized string
  - stripEnclosingDoubleQuotes
```
public static String stripEnclosingDoubleQuotes(String str)
```
    Strips enclosing double quotes.
    
    Parameters:
    
    str - the original string
    
    Returns:
    
    the string with its double quotes removed
  - toFixedLength
```
public static String toFixedLength(String str,
                                   int length,
                                   char filler)
```
    Takes a string and returns one with a given length, cutting or filling up with fillchars, whatever appropriate.
    
    Parameters:
    
    str - the string
    
    length - the length of the returned string
    
    filler - the character to fill up if str is too short
    
    Returns:
    
    the string with the desired length
  - toFixedLength
```
public static String toFixedLength(String str,
                                   int length)
```
    Takes a string and returns one with a given length, cutting or filling up with spaces, whatever appropriate.
    
    Parameters:
    
    str - the string
    
    length - the length of the returned string
    
    Returns:
    
    the string with the desired length
  - toFixedLengthLeftFill
```
public static String toFixedLengthLeftFill(String str,
                                           int length,
                                           char filler)
```
    Takes a string and returns one with a given length, cutting or filling up with fillchars from the left, whatever appropriate.
    
    Parameters:
    
    str - the string
    
    length - the length of the returned string
    
    filler - the character to fill up if str is too short
    
    Returns:
    
    the string with the desired length
  - toFixedLengthLeftFill
```
public static String toFixedLengthLeftFill(String str,
                                           int length)
```
    Takes a string and returns one with a given length, cutting or filling up with spaces from the left, whatever appropriate.
    
    Parameters:
    
    str - the string
    
    length - the length of the returned string
    
    Returns:
    
    the string with the desired length
  - toDTA
```
public static String toDTA(String str)
```
    Filters illegal chars for DTA-Files (German "DATENAUSTAUSCH" banking format).
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the DTA conform string
  - toVarName
```
public static String toVarName(String str)
```
    Filters illegal chars for Java variable names.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the java conform string
  - isAllDigits
```
public static boolean isAllDigits(String str,
                                  boolean whitespaceAllowed)
```
    Checks if a string contains only digits or whitespaces, i.e. no illegal char in a number string.
    
    Parameters:
    
    str - the string to check
    
    whitespaceAllowed - true if whitespaces are allowed
    
    Returns:
    
    true if no illegal char detected, false otherwise
  - isAllDigits
```
public static boolean isAllDigits(String str)
```
    checks if a string contains only digits, i.e. no non-number char in string, even no whitespace.
    
    Parameters:
    
    str - the string to check
    
    Returns:
    
    true if no illegal char detected, false otherwise
  - trim
```
public static String trim(String s,
                          int max)
```
    Trims a string. The method is nullpointer safe.
    
    Parameters:
    
    s - the string, may be null
    
    max - the maximum number of characters, 0 = minimum length
    
    Returns:
    
    the trimmed string, null if s == null
  - trim
```
public static String trim(String s)
```
    Trims a string. The method is nullpointer safe.
    
    Parameters:
    
    s - the string, may be null
    
    Returns:
    
    the trimmed string, null if s == null
    
    See Also:
    
    trim(java.lang.String, int)
  - trimRight
```
public static String trimRight(String str,
                               char filler)
```
    Cuts trailing characters.
    Removes all trailing characters of given value from the string. If the string consists of those characters only, the returned string will empty.
    
    Parameters:
    
    str - the string
    
    filler - the filler to remove
    
    Returns:
    
    the trimmed string, never null
  - trimLeft
```
public static String trimLeft(String str,
                              char filler)
```
    Cuts leading characters.
    Removes all leading characters of given value from the string. If the string consists of those characters only, the returned string will be empty.
    
    Parameters:
    
    str - the string
    
    filler - the filler to remove
    
    Returns:
    
    the trimmed string, never null
  - fillLeft
```
public static String fillLeft(String str,
                              int length,
                              char filler)
```
    Fills up a string from the left with a filler character to match a given length.
    If the string is already longer, nothing happens.
    
    Parameters:
    
    str - the string
    
    length - the desired length
    
    filler - the filler character
    
    Returns:
    
    the filled string, never null
  - fillRight
```
public static String fillRight(String str,
                               int length,
                               char filler)
```
    Fills up a string to the right with a filler character to match a given length.
    If the string is already longer, nothing happens.
    
    Parameters:
    
    str - the string
    
    length - the desired length
    
    filler - the filler character
    
    Returns:
    
    the filled string, never null
  - firstBefore
```
public static String firstBefore(String str,
                                 char delimiter)
```
    Gets the part of a string before a given delimiter.
    
    Parameters:
    
    str - the string
    
    delimiter - the delimiter
    
    Returns:
    
    the first part up to but excluding delimiter or the string if no delimiter at all
  - lastAfter
```
public static String lastAfter(String str,
                               char delimiter)
```
    Gets the part of a string after a given delimiter.
    
    Parameters:
    
    str - the string
    
    delimiter - the delimiter
    
    Returns:
    
    the last part following delimiter or the string if no delimiter at all
  - firstLine
```
public static String firstLine(String str)
```
    Gets the first line from a multi-line string. Nice in tables.
    
    Parameters:
    
    str - the multiline string
    
    Returns:
    
    the first line, null if str == null
  - toHexString
```
public static String toHexString(byte[] binaryData)
```
    Creates a human-readable hex-String out of a byte-array (e.g. from MessageDigest MD5sum).
    
    Parameters:
    
    binaryData - the data, may be null
    
    Returns:
    
    the formatted hex string , null if data was null
  - toBytes
```
public static byte[] toBytes(char c)
```
    Converts a single (unicode) char to a byte-array.
    
    Parameters:
    
    c - the character
    
    Returns:
    
    the byte[2] array
  - toBytes
```
public static byte[] toBytes(char[] chars)
```
    Converts a char-array to a byte-array.
    
    Parameters:
    
    chars - the character array
    
    Returns:
    
    the byte array, empty if chars is null
  - hash
```
public static String hash(String algorithm,
                          char[] salt,
                          char[] input)
```
    Builds a hash from an array of chars.
    Note that this method converts the characters to bytes via toBytes(char[]) before applying the hash.
    
    Parameters:
    
    algorithm - the hashing algorithm (MD5, SHA-1, SHA-256 are supported by all java runtimes, at least)
    
    salt - the "salt", null if plain hash
    
    input - is the input array of chars
    
    Returns:
    
    the hash as a string, null if input == null
  - objectToLoggableString
```
public static String objectToLoggableString(Object object)
```
    Converts a value to a loggable string.
    
    Parameters:
    
    object - the object
    
    Returns:
    
    the string
  - countOccurrences
```
public static int countOccurrences(String str,
                                   char c)
```
    Counts the number of occurrences of a given character in a string.
    
    Parameters:
    
    str - the string to test
    
    c - the character to check for
    
    Returns:
    
    the number of times c is part of str
  - objectArrayToString
```
public static String objectArrayToString(Object[] objArray,
                                         String separator)
```
    Creates a string from an object array.
    
    Parameters:
    
    objArray - the array of objects
    
    separator - the string between two objects
    
    Returns:
    
    the string
  - toCharArray
```
public static char[] toCharArray(String str)
```
    Transforms a string to a char-array. nullp-safe.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the character array
  - fill
```
public static void fill(char[] buf,
                        char val)
```
    Null-safe char array filler.
    
    Parameters:
    
    buf - the char buffer, may be null
    
    val - the value to fill
    
    See Also:
    
    Arrays.fill(char[], char)
  - blank
```
public static void blank(char[] buf)
```
    Null-safe char array filler.
    Fills with blanks.
    
    Parameters:
    
    buf - the char buff, may be null
    
    See Also:
    
    fill(char[], char)
  - toHTML
```
public static String toHTML(String text)
```
    Converts a multiline string to an HTML-string that can be displayed in a label. Useful to print multiline labels.
    
    Parameters:
    
    text - the input string
    
    Returns:
    
    the HTML string
  - removeTrailingText
```
public static String removeTrailingText(String str,
                                        String trail)
```
    Removes a trailing text from a string.
    
    Parameters:
    
    str - the original string
    
    trail - the trailing string to remove, if found
    
    Returns:
    
    the shortened text
  - toAsciiLetterOrDigit
```
public static String toAsciiLetterOrDigit(String str)
```
    Converts to string containing only the letters A-z or digits.
    All other characters will be converted to an underscore. All diacrits will be converted first (see unDiacrit(java.lang.String, boolean). The resulting string will not contain more than one underscore in a row.
    Nice to create filenames.
    
    Parameters:
    
    str - the string
    
    Returns:
    
    the filename

Class StringHelper

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

maxLogCollectionSize

stringNormalizer

Method Detail

equalsIgnoreCase

toUpper

toLower

firstToUpper

firstToLower

getPlainClassName

getContinuedLine

toDoubleQuotes

parseString

toParsableString

split

isValidJavaClassName

isValidJavaPackageName

isValidJavaIdentifier

readTextFromResource

isAllWhitespace

isReservedWord

digitToString

unDiacrit

normalize

normalize

stripEnclosingDoubleQuotes

toFixedLength

toFixedLength

toFixedLengthLeftFill

toFixedLengthLeftFill

toDTA

toVarName

isAllDigits

isAllDigits

trim

trim

trimRight

trimLeft

fillLeft

fillRight

firstBefore

lastAfter

firstLine

toHexString

toBytes

toBytes

hash

objectToLoggableString

countOccurrences

objectArrayToString

toCharArray

fill

blank

toHTML

removeTrailingText

toAsciiLetterOrDigit