org.starchartlabs.alloy.core

Class Strings

java.lang.Object

org.starchartlabs.alloy.core.Strings

public final class Strings
extends java.lang.Object

Utilities intended to enhance and streamline use of String or CharSequence instances.

Since:

0.1.0

Method Summary

Modifier and Type	Method and Description
static java.lang.String	commonPrefix(java.lang.CharSequence a, java.lang.CharSequence b)
static java.lang.String	commonSuffix(java.lang.CharSequence a, java.lang.CharSequence b)
static java.lang.String	emptyToNull(java.lang.String string) Returns the given string if it is nonempty; null otherwise
static java.lang.String	format(java.lang.String template, java.lang.Object... args) Returns a formatted string using the specified template string and arguments.
static boolean	isNullOrEmpty(java.lang.String string) Returns true if the given string is null or is the empty string.
static java.lang.String	nullToEmpty(java.lang.String string) Returns the given string if it is non-null; the empty string otherwise
static java.lang.String	padEnd(java.lang.String string, int minLength, char padChar) Constructs a string, of length at least minLength, consisting of string appended with as many copies of padChar as are necessary to reach that length.
static java.lang.String	padStart(java.lang.String string, int minLength, char padChar) Constructs a string, of length at least minLength, consisting of string prepended with as many copies of padChar as are necessary to reach that length.
static java.lang.String	repeat(java.lang.String string, int count) Constructs a string consisting of a specific number of concatenated copies of an input string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

nullToEmpty

public static java.lang.String nullToEmpty(@Nullable
                                           java.lang.String string)

Returns the given string if it is non-null; the empty string otherwise

Parameters:

string - The string to test and possibly return

Returns:

string itself if it is non-null; "" if it is null

emptyToNull

@Nullable
public static java.lang.String emptyToNull(@Nullable
                                                      java.lang.String string)

Returns the given string if it is nonempty; null otherwise

Parameters:

string - The string to test and possibly return

Returns:

string itself if it is nonempty; null if it is empty or null

Since:

0.1.0

isNullOrEmpty

public static boolean isNullOrEmpty(@Nullable
                                    java.lang.String string)

Returns true if the given string is null or is the empty string.

Consider normalizing your string references with nullToEmpty(java.lang.String). If you do, you can use String.isEmpty() instead of this method, and you won't need special null-safe forms of methods like String.toUpperCase(java.util.Locale) either. Or, if you'd like to normalize "in the other direction," converting empty strings to null, you can use emptyToNull(java.lang.String).

Parameters:

string - A string reference to check

Returns:

true if the string is null or the empty string, false otherwise

Since:

0.1.0

padStart

public static java.lang.String padStart(java.lang.String string,
                                        int minLength,
                                        char padChar)

Constructs a string, of length at least minLength, consisting of string prepended with as many copies of padChar as are necessary to reach that length. For example,

• padStart("7", 3, '0') returns "007"
• padStart("2010", 3, '0') returns "2010"

See Formatter for a richer set of formatting capabilities.

Parameters:

string - The string which should appear at the end of the result

minLength - The minimum length the resulting string must have. Can be zero or negative, in which case the input string is always returned

padChar - The character to insert at the beginning of the result until the minimum length is reached

Returns:

A padded string of at least minLength characters which ends with string

Since:

0.1.0

padEnd

public static java.lang.String padEnd(java.lang.String string,
                                      int minLength,
                                      char padChar)

Constructs a string, of length at least minLength, consisting of string appended with as many copies of padChar as are necessary to reach that length. For example,

• padEnd("4.", 5, '0') returns "4.000"
• padEnd("2010", 3, '!') returns "2010"

See Formatter for a richer set of formatting capabilities.

Parameters:

string - The string which should appear at the beginning of the result

minLength - The minimum length the resulting string must have. Can be zero or negative, in which case the input string is always returned

padChar - The character to append to the end of the result until the minimum length is reached

Returns:

A padded string of at least minLength characters which starts with string

Since:

0.1.0

repeat

public static java.lang.String repeat(java.lang.String string,
                                      int count)

Constructs a string consisting of a specific number of concatenated copies of an input string. For example, repeat("hey", 3) returns the string "heyheyhey".

Parameters:

string - A non-null string to repeat

count - The number of times to repeat the provided string; Must be nonnegative

Returns:

A string containing string repeated count times, or the empty string if count is zero

Throws:

java.lang.IllegalArgumentException - If count is negative

Since:

0.1.0

commonPrefix

public static java.lang.String commonPrefix(java.lang.CharSequence a,
                                            java.lang.CharSequence b)

Parameters:

a - One of two sequences to find the longest common prefix of

b - One of two sequences to find the longest common prefix of

Returns:

The longest string prefix such that a.toString().startsWith(prefix) and b.toString().startsWith(prefix), without splitting surrogate pairs. If a and b have no common prefix, returns the empty string

Since:

0.1.0

commonSuffix

public static java.lang.String commonSuffix(java.lang.CharSequence a,
                                            java.lang.CharSequence b)

Parameters:

a - One of two sequences to find the longest common suffix of

b - One of two sequences to find the longest common suffix of

Returns:

The longest string suffix such that a.toString().endsWith(suffix) and b.toString().endsWith(suffix), without splitting surrogate pairs. If a and b have no common suffix, returns empty string

Since:

0.1.0

format

public static java.lang.String format(@Nullable
                                      java.lang.String template,
                                      @Nullable
                                      java.lang.Object... args)

Returns a formatted string using the specified template string and arguments. Only %s placeholder substitution is supported

Provided in addition to the standard Java String.format(String, Object[]) for performance reasons - this implementation is intended for more performance-sensitive applications

It is highly recommended to use this functionality where execution is deferred, such as operations which accept a Supplier

Parameters:

template - A template for a formatted message. The message is formed by replacing each %s placeholder in the template with an argument. These are matched by position - the first %s gets args[0], etc. Unmatched arguments will be appended to the formatted message in square braces. Unmatched placeholders will be left as-is.

args - The arguments to be substituted into the message template. Arguments are converted to strings using String.valueOf(Object).

Returns:

A formatted message with provided arguments substituted

Since:

0.1.0