Class StringUtils

java.lang.Object

org.codehaus.plexus.util.StringUtils

public class StringUtils
extends Object

Common String manipulation routines.

Originally from Turbine and the GenerationJavaCore library.

Since:

1.0

Author:

Jon S. Stevens, Daniel Rall, Greg Coladonato, Henri Yandell, Ed Korthof, Rand McNeely, Stephen Colebourne, Fredrik Westermarck, Holger Krauth, Alexander Day Chaffee, Vincent Siveton

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 s, int maxWidth)
static String	abbreviate(String s, int offset, int maxWidth)
static String	addAndDeHump(String view)
static String	capitalise(String str)	Capitalise a String.
static String	capitaliseAllWords(String str)	Capitalise all the words in a String.
static String	capitalizeFirstLetter(String data)
static String	center(String str, int size)	Center a String in a larger String of size n.
static String	center(String str, int size, String delim)	Center a String in a larger String of size n.
static String	chomp(String str)	Remove the last newline, and everything after it from a String.
static String	chomp(String str, String sep)	Remove the last value of a supplied String, and everything after it from a String.
static String	chompLast(String str)	Remove a newline if and only if it is at the end of the supplied String.
static String	chompLast(String str, String sep)	Remove a value if and only if the String ends with that value.
static String	chop(String str)	Remove the last character from a String.
static String	chopNewline(String str)	Remove \n from end of a String if it's there.
static String	clean(String str)	Removes control characters, including whitespace, from both ends of this String, handling null by returning an empty String.
static String	concatenate(Object[] array)	Concatenates elements of an array into a single String.
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 int	countMatches(String str, String sub)	How many times is the substring in the larger String.
static String	defaultString(Object obj)	Deprecated.
static String	defaultString(Object obj, String defaultString)	Deprecated.
static String	deleteWhitespace(String str)	Deletes all whitespaces from a String.
static String	difference(String s1, String s2)	Compare two strings, and return the portion where they differ.
static int	differenceAt(String s1, String s2)	Compare two strings, and return the index at which the strings begin to differ.
static boolean	equals(String str1, String str2)	Deprecated.
static boolean	equalsIgnoreCase(String str1, String str2)	Compares two Strings, returning true if they are equal ignoring the case.
static String	escape(String str)	Escapes any values it finds into their String form.
static String	escape(String source, char[] escapedChars, char escapeChar)
static String	escape(String source, char[] escapedChars, String escapePattern)
static String	getChomp(String str, String sep)	Remove everything and return the last value of a supplied String, and everything after it from a String.
static String	getNestedString(String str, String tag)	Get the String that is nested in between two instances of the same String.
static String	getNestedString(String str, String open, String close)	Get the String that is nested in between two Strings.
static String	getPrechomp(String str, String sep)	Remove and return everything before the first value of a supplied String from another String.
static int	indexOfAny(String str, String[] searchStrs)	Find the first index of any of a set of potential substrings.
static String	interpolate(String text, Map<?,?> namespace)
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	isBlank(String str)	Checks if a String is whitespace, empty ("") or null.
static boolean	isEmpty(String str)	Checks if a String is null or empty.
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 non null and is not empty (length > 0).
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, String separator)	Joins the elements of the provided array into a single String containing the provided list of 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	lastIndexOfAny(String str, String[] searchStrs)	Find the latest index of any of a set of potential substrings.
static String	left(String str, int len)	Gets the leftmost n characters of a String.
static String	leftPad(String str, int size)	Left pad a String with spaces.
static String	leftPad(String str, int size, String delim)	Left pad a String with a specified string.
static String	lowerCase(String str)	Convert a String to lower case, null String returns null.
static String	lowercaseFirstLetter(String data)
static String	mid(String str, int pos, int len)	Gets n characters from the middle of a String.
static String	overlayString(String text, String overlay, int start, int end)	Overlay a part of a String with another String.
static String	prechomp(String str, String sep)	Remove the first value of a supplied String, and everything before it from a String.
static String	quoteAndEscape(String source, char quoteChar)	Quote and escape a String with the given character, handling null.
static String	quoteAndEscape(String source, char quoteChar, char[] quotingTriggers)	Quote and escape a String with the given character, handling null.
static String	quoteAndEscape(String source, char quoteChar, char[] escapedChars, char[] quotingTriggers, char escapeChar, boolean force)
static String	quoteAndEscape(String source, char quoteChar, char[] escapedChars, char[] quotingTriggers, String escapePattern, boolean force)
static String	quoteAndEscape(String source, char quoteChar, char[] escapedChars, char escapeChar, boolean force)
static String	removeAndHump(String data, String replaceThis)
static String	removeDuplicateWhitespace(String s)	Remove all duplicate whitespace characters and line terminators are replaced with a single space.
static String	repeat(String str, int repeat)	Repeat a String n times to form a new string.
static String	replace(String text, char repl, char with)	Replace all occurrences of a char within another char.
static String	replace(String text, char repl, char with, int max)	Replace a char with another char inside a larger String, for the first max values of the search char.
static String	replace(String text, String repl, String with)	Replace all occurrences of a String within another String.
static String	replace(String text, String repl, String with, int max)	Replace a String with another String inside a larger String, for the first max values of the search String.
static String	replaceOnce(String text, char repl, char with)	Replace a char with another char inside a larger String, once.
static String	replaceOnce(String text, String repl, String with)	Replace a String with another String inside a larger String, once.
static String	reverse(String str)	Reverse a String.
static String	reverseDelimitedString(String str, String delimiter)	Reverses a String that is delimited by a specific character.
static String	right(String str, int len)	Gets the rightmost n characters of a String.
static String	rightPad(String str, int size)	Right pad a String with spaces.
static String	rightPad(String str, int size, String delim)	Right pad a String with a specified string.
static String[]	split(String str)	Splits the provided text into a array, using whitespace as the separator.
static String[]	split(String text, String separator)
static String[]	split(String str, String separator, int max)	Splits the provided text into a array, based on a given separator.
static String	strip(String str)	Remove whitespace from the front and back of a String.
static String	strip(String str, String delim)	Remove a specified String from the front and back of a String.
static String[]	stripAll(String[] strs)	Strip whitespace from the front and back of every String in the array.
static String[]	stripAll(String[] strs, String delimiter)	Strip the specified delimiter from the front and back of every String in the array.
static String	stripEnd(String str, String strip)	Strip any of a supplied String from the end of a String.
static String	stripStart(String str, String strip)	Strip any of a supplied String from the start of a String.
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	swapCase(String str)	Swaps the case of String.
static String	trim(String str)	Removes control characters, including whitespace, from both ends of this String, handling null by returning null.
static String	uncapitalise(String str)	Uncapitalise a String.
static String	uncapitaliseAllWords(String str)	Uncapitalise all the words in a string.
static String	unifyLineSeparators(String s)	Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
static String	unifyLineSeparators(String s, String ls)	Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
static String	upperCase(String str)	Convert a String to upper case, null String returns null.

Methods inherited from class java.lang.Object

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

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 manager to operate.

Method Details

clean

public static String clean(String str)

Removes control characters, including whitespace, from both ends of this String, handling null by returning an empty String.

Parameters:

str - the String to check

Returns:

the trimmed text (never null)

See Also:

• String.trim()

trim

public static String trim(String str)

Removes control characters, including whitespace, from both ends of this String, handling null by returning null.

Parameters:

str - the String to check

Returns:

the trimmed text (or null)

See Also:

• String.trim()

deleteWhitespace

public static String deleteWhitespace(String str)

Deletes all whitespaces from a String.

Whitespace is defined by Character.isWhitespace(char).

Parameters:

str - String target to delete whitespace from

Returns:

the String without whitespaces

isNotEmpty

public static boolean isNotEmpty(String str)

Checks if a String is non null and is not empty (length > 0).

Parameters:

str - the String to check

Returns:

true if the String is non-null, and not length zero

isEmpty

public static boolean isEmpty(String str)

Checks if a String is null or empty.

Note: In releases prior 3.5.0, this method trimmed the input string such that it worked the same as isBlank(String). Since release 3.5.0 it no longer returns true for strings containing only whitespace characters.

Parameters:

str - the String to check

Returns:

true if the String is null, or length zero

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:

1.5.2

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:

1.5.2

equals

@Deprecated
public static boolean equals(String str1,
 String str2)

Deprecated.

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.

Parameters:

str1 - the first string

str2 - the second string

Returns:

true if the Strings are equal, case sensitive, or both null

See Also:

• String.equals(Object)
• Objects.equals(Object, 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.

Parameters:

str1 - the first string

str2 - the second string

Returns:

true if the Strings are equal, case insensitive, or both null

See Also:

• String.equalsIgnoreCase(String)

indexOfAny

public static int indexOfAny(String str,
 String[] searchStrs)

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

null String will return -1.

Parameters:

str - the String to check

searchStrs - the Strings to search for

Returns:

the first index of any of the searchStrs in str

Throws:

NullPointerException - if any of searchStrs[i] is null

lastIndexOfAny

public static int lastIndexOfAny(String str,
 String[] searchStrs)

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

null string will return -1.

Parameters:

str - the String to check

searchStrs - the Strings to search for

Returns:

the last index of any of the Strings

Throws:

NullPointerException - if any of searchStrs[i] is null

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.

Parameters:

str - the String to get the substring from

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

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.

Parameters:

str - the String to get the substring from

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 position

left

public static String left(String str,
 int len)

Gets the leftmost n characters of a String.

If n characters are not available, or the String is null, the String will be returned without an exception.

Parameters:

str - the String to get the leftmost characters from

len - the length of the required String

Returns:

the leftmost characters

Throws:

IllegalArgumentException - if len is less than zero

right

public static String right(String str,
 int len)

Gets the rightmost n characters of a String.

If n characters are not available, or the String is null, the String will be returned without an exception.

Parameters:

str - the String to get the rightmost characters from

len - the length of the required String

Returns:

the leftmost characters

Throws:

IllegalArgumentException - if len is less than zero

mid

public static String mid(String str,
 int pos,
 int len)

Gets n characters from the middle of a String.

If n characters are not available, the remainder of the String will be returned without an exception. If the String is null, null will be returned.

Parameters:

str - the String to get the characters from

pos - the position to start from

len - the length of the required String

Returns:

the leftmost characters

Throws:

IndexOutOfBoundsException - if pos is out of bounds

IllegalArgumentException - if len is less than zero

split

public static String[] split(String str)

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

The separator is not included in the returned String array.

Parameters:

str - the String to parse

Returns:

an array of parsed Strings

split

public static String[] split(String text,
 String separator)

Parameters:

text - The string to parse.

separator - Characters used as the delimiters. If null, splits on whitespace.

Returns:

an array of parsed Strings

split

public static String[] split(String str,
 String separator,
 int max)

Splits the provided text into a array, based on a given separator.

The separator is not included in the returned String array. The maximum number of splits to perform can be controlled. A null separator will cause parsing to be on whitespace.

This is useful for quickly splitting a String directly into an array of tokens, instead of an enumeration of tokens (as StringTokenizer does).

Parameters:

str - The string to parse.

separator - Characters used as the delimiters. If 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

concatenate

public static String concatenate(Object[] array)

Concatenates elements of an array into a single String.

The difference from join is that concatenate has no delimiter.

Parameters:

array - the array of values to concatenate.

Returns:

the concatenated string.

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 a blank String.

Parameters:

array - the array of values to join together

separator - the separator character to use

Returns:

the joined String

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 a blank String.

Parameters:

iterator - the Iterator of values to join together

separator - the separator character to use

Returns:

the joined String

replaceOnce

public static String replaceOnce(String text,
 char repl,
 char with)

Replace a char with another char inside a larger String, once.

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - char to search for

with - char to replace with

Returns:

the text with any replacements processed

See Also:

• replace(String text, char repl, char with, int max)

replace

public static String replace(String text,
 char repl,
 char with)

Replace all occurrences of a char within another char.

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - char to search for

with - char to replace with

Returns:

the text with any replacements processed

See Also:

• replace(String text, char repl, char with, int max)

replace

public static String replace(String text,
 char repl,
 char with,
 int max)

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

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - char to search for

with - char to replace with

max - maximum number of values to replace, or -1 if no maximum

Returns:

the text with any replacements processed

replaceOnce

public static String replaceOnce(String text,
 String repl,
 String with)

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

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - String to search for

with - String to replace with

Returns:

the text with any replacements processed

See Also:

• replace(String text, String repl, String with, int max)

replace

public static String replace(String text,
 String repl,
 String with)

Replace all occurrences of a String within another String.

A null reference passed to this method is a no-op.

Parameters:

text - text to search and replace in

repl - String to search for

with - String to replace with

Returns:

the text with any replacements processed

See Also:

• replace(String text, String repl, String with, int max)

replace

public static String replace(String text,
 String repl,
 String with,
 int max)

Replace 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.

Parameters:

text - text to search and replace in

repl - String to search for

with - String to replace with

max - maximum number of values to replace, or -1 if no maximum

Returns:

the text with any replacements processed

overlayString

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

Overlay a part of a String with another String.

Parameters:

text - String to do overlaying in

overlay - String to overlay

start - int to start overlaying at

end - int to stop overlaying before

Returns:

String with overlayed text

Throws:

NullPointerException - if text or overlay is null

center

public static String center(String str,
 int size)

Center a String in a larger String of size n.

Uses spaces as the value to buffer the String with. Equivalent to center(str, size, " ").

Parameters:

str - String to center

size - int size of new String

Returns:

String containing centered String

Throws:

NullPointerException - if str is null

center

public static String center(String str,
 int size,
 String delim)

Center a String in a larger String of size n.

Uses a supplied String as the value to buffer the String with.

Parameters:

str - String to center

size - int size of new String

delim - String to buffer the new String with

Returns:

String containing centered String

Throws:

NullPointerException - if str or delim is null

ArithmeticException - if delim is the empty String

chomp

public static String chomp(String str)

Remove the last newline, and everything after it from a String.

Parameters:

str - String to chomp the newline from

Returns:

String without chomped newline

Throws:

NullPointerException - if str is null

chomp

public static String chomp(String str,
 String sep)

Remove the last value of a supplied String, and everything after it from a String.

Parameters:

str - String to chomp from

sep - String to chomp

Returns:

String without chomped ending

Throws:

NullPointerException - if str or sep is null

chompLast

public static String chompLast(String str)

Remove a newline if and only if it is at the end of the supplied String.

Parameters:

str - String to chomp from

Returns:

String without chomped ending

Throws:

NullPointerException - if str is null

chompLast

public static String chompLast(String str,
 String sep)

Remove a value if and only if the String ends with that value.

Parameters:

str - String to chomp from

sep - String to chomp

Returns:

String without chomped ending

Throws:

NullPointerException - if str or sep is null

getChomp

public static String getChomp(String str,
 String sep)

Remove everything and return the last value of a supplied String, and everything after it from a String.

Parameters:

str - String to chomp from

sep - String to chomp

Returns:

String chomped

Throws:

NullPointerException - if str or sep is null

prechomp

public static String prechomp(String str,
 String sep)

Remove the first value of a supplied String, and everything before it from a String.

Parameters:

str - String to chomp from

sep - String to chomp

Returns:

String without chomped beginning

Throws:

NullPointerException - if str or sep is null

getPrechomp

public static String getPrechomp(String str,
 String sep)

Remove and return everything before the first value of a supplied String from another String.

Parameters:

str - String to chomp from

sep - String to chomp

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.

Parameters:

str - String to chop last character from

Returns:

String without last character

Throws:

NullPointerException - if str is null

chopNewline

public static String chopNewline(String str)

Remove \n from end of a String if it's there. If a \r precedes it, then remove that too.

Parameters:

str - String to chop a newline from

Returns:

String without newline

Throws:

NullPointerException - if str is null

escape

public static String escape(String str)

Escapes any values it finds into their String form.

So a tab becomes the characters '\\' and 't'.

Parameters:

str - String to escape values in

Returns:

String with escaped values

Throws:

NullPointerException - if str is null

repeat

public static String repeat(String str,
 int repeat)

Repeat a String n times to form a new string.

Parameters:

str - String to repeat

repeat - number of times to repeat str

Returns:

String with repeated String

Throws:

NegativeArraySizeException - if repeat < 0

NullPointerException - if str is null

rightPad

public static String rightPad(String str,
 int size)

Right pad a String with spaces.

The String is padded to the size of n.

Parameters:

str - String to repeat

size - number of times to repeat str

Returns:

right padded String

Throws:

NullPointerException - if str is null

rightPad

public static String rightPad(String str,
 int size,
 String delim)

Right pad a String with a specified string.

The String is padded to the size of n.

Parameters:

str - String to pad out

size - size to pad to

delim - String to pad with

Returns:

right padded String

Throws:

NullPointerException - if str or delim is null

ArithmeticException - if delim is the empty String

leftPad

public static String leftPad(String str,
 int size)

Left pad a String with spaces.

The String is padded to the size of n.

Parameters:

str - String to pad out

size - size to pad to

Returns:

left padded String

Throws:

NullPointerException - if str or delim is null

leftPad

public static String leftPad(String str,
 int size,
 String delim)

Left pad a String with a specified string. Pad to a size of n.

Parameters:

str - String to pad out

size - size to pad to

delim - String to pad with

Returns:

left padded String

Throws:

NullPointerException - if str or delim is null

ArithmeticException - if delim is the empty string

strip

public static String strip(String str)

Remove whitespace from the front and back of a String.

Parameters:

str - the String to remove whitespace from

Returns:

the stripped String

strip

public static String strip(String str,
 String delim)

Remove a specified String from the front and back of a String.

If whitespace is wanted to be removed, used the strip(java.lang.String) method.

Parameters:

str - the String to remove a string from

delim - the String to remove at start and end

Returns:

the stripped String

stripAll

public static String[] stripAll(String[] strs)

Strip whitespace from the front and back of every String in the array.

Parameters:

strs - the Strings to remove whitespace from

Returns:

the stripped Strings

stripAll

public static String[] stripAll(String[] strs,
 String delimiter)

Strip the specified delimiter from the front and back of every String in the array.

Parameters:

strs - the Strings to remove a String from

delimiter - the String to remove at start and end

Returns:

the stripped Strings

stripEnd

public static String stripEnd(String str,
 String strip)

Strip any of a supplied String from the end of a String.

If the strip String is null, whitespace is stripped.

Parameters:

str - the String to remove characters from

strip - the String to remove

Returns:

the stripped String

stripStart

public static String stripStart(String str,
 String strip)

Strip any of a supplied String from the start of a String.

If the strip String is null, whitespace is stripped.

Parameters:

str - the String to remove characters from

strip - the String to remove

Returns:

the stripped String

upperCase

public static String upperCase(String str)

Convert a String to upper case, null String returns null.

Parameters:

str - the String to uppercase

Returns:

the upper cased String

lowerCase

public static String lowerCase(String str)

Convert a String to lower case, null String returns null.

Parameters:

str - the string to lowercase

Returns:

the lower cased String

uncapitalise

public static String uncapitalise(String str)

Uncapitalise a String.

That is, convert the first character into lower-case. null is returned as null.

Parameters:

str - the String to uncapitalise

Returns:

uncapitalised String

capitalise

public static String capitalise(String str)

Capitalise a String.

That is, convert the first character into title-case. null is returned as null.

Parameters:

str - the String to capitalise

Returns:

capitalised String

swapCase

public static String swapCase(String str)

Swaps the case of String.

Properly looks after making sure the start of words are Titlecase and not Uppercase.

null is returned as null.

Parameters:

str - the String to swap the case of

Returns:

the modified String

capitaliseAllWords

public static String capitaliseAllWords(String str)

Capitalise all the words in a String.

Uses Character.isWhitespace(char) as a separator between words.

null will return null.

Parameters:

str - the String to capitalise

Returns:

capitalised String

uncapitaliseAllWords

public static String uncapitaliseAllWords(String str)

Uncapitalise all the words in a string.

Uses Character.isWhitespace(char) as a separator between words.

null will return null.

Parameters:

str - the string to uncapitalise

Returns:

uncapitalised string

getNestedString

public static String getNestedString(String str,
 String tag)

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

If str is null, will return null.

Parameters:

str - the String containing nested-string

tag - the String before and after nested-string

Returns:

the String that was nested, or null

Throws:

NullPointerException - if tag is null

getNestedString

public static String getNestedString(String str,
 String open,
 String close)

Get the String that is nested in between two Strings.

Parameters:

str - the String containing nested-string

open - the String before nested-string

close - the String after nested-string

Returns:

the String that was nested, or null

Throws:

NullPointerException - if open or close is null

countMatches

public static int countMatches(String str,
 String sub)

How many times is the substring in the larger String.

null returns 0.

Parameters:

str - the String to check

sub - the substring to count

Returns:

the number of occurrences, 0 if the String is null

Throws:

NullPointerException - if sub is null

isAlpha

public static boolean isAlpha(String str)

Checks if the String contains only unicode letters.

null will return false. An empty String will return true.

Parameters:

str - the String to check

Returns:

true if only contains letters, 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 will return true.

Parameters:

str - the String to check

Returns:

true if only contains whitespace, 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 will return true.

Parameters:

str - the String to check

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 will return true.

Parameters:

str - the String to check

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 will return true.

Parameters:

str - the String to check

Returns:

true if only contains letters, digits or space, and is non-null

isNumeric

public static boolean isNumeric(String str)

Checks if the String contains only unicode digits.

null will return false. An empty String will return true.

Parameters:

str - the String to check

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 (' ').

null will return false. An empty String will return true.

Parameters:

str - the String to check

Returns:

true if only contains digits or space, and is non-null

defaultString

@Deprecated
public static String defaultString(Object obj)

Deprecated.

Returns either the passed in Object as a String, or, if the Object is null, an empty String.

Parameters:

obj - the Object to check

Returns:

the passed in Object's toString, or blank if it was null

See Also:

• Objects.toString(Object, String)

defaultString

@Deprecated
public static String defaultString(Object obj,
 String defaultString)

Deprecated.

Returns either the passed in Object as a String, or, if the Object is null, a passed in default String.

Parameters:

obj - the Object to check

defaultString - the default String to return if str is null

Returns:

the passed in string, or the default if it was null

See Also:

• Objects.toString(Object, String)

reverse

public static String reverse(String str)

Reverse a String.

null String returns null.

Parameters:

str - the String to reverse

Returns:

the reversed String

reverseDelimitedString

public static String reverseDelimitedString(String str,
 String delimiter)

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 '.').

Parameters:

str - the String to reverse

delimiter - the delimiter to use

Returns:

the reversed String

abbreviate

public static String abbreviate(String s,
 int maxWidth)

Parameters:

s - string

maxWidth - maximum length of result string

Returns:

Turn "Now is the time for all good men" into "Now is the time for..."

Specifically:

If str is less than max characters long, return it. Else abbreviate it to (substring(str, 0, max-3) + "..."). If maxWidth is less than 3, throw an IllegalArgumentException. In no case will it return a string of length greater than maxWidth.

abbreviate

public static String abbreviate(String s,
 int offset,
 int maxWidth)

Parameters:

s - string

offset - left edge of source string

maxWidth - maximum length of result string

Returns:

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.

difference

public static String difference(String s1,
 String s2)

Compare two strings, and return the portion where they differ. (More precisely, return the remainder of the second string, starting from where it's different from the first.)

E.g. strdiff("i am a machine", "i am a robot") -> "robot"

Parameters:

s1 - string

s2 - string

Returns:

the portion of s2 where it differs from s1; returns the empty string ("") if they are equal

differenceAt

public static int differenceAt(String s1,
 String s2)

Compare two strings, and return the index at which the strings begin to differ.

E.g. strdiff("i am a machine", "i am a robot") -> 7

Parameters:

s1 - string

s2 - string

Returns:

the index where s2 and s1 begin to differ; -1 if they are equal

interpolate

public static String interpolate(String text,
 Map<?,?> namespace)

removeAndHump

public static String removeAndHump(String data,
 String replaceThis)

capitalizeFirstLetter

public static String capitalizeFirstLetter(String data)

lowercaseFirstLetter

public static String lowercaseFirstLetter(String data)

addAndDeHump

public static String addAndDeHump(String view)

quoteAndEscape

public static String quoteAndEscape(String source,
 char quoteChar)

Quote and escape a String with the given character, handling null.

 StringUtils.quoteAndEscape(null, *)    = null
 StringUtils.quoteAndEscape("", *)      = ""
 StringUtils.quoteAndEscape("abc", '"') = abc
 StringUtils.quoteAndEscape("a\"bc", '"') = "a\"bc"
 StringUtils.quoteAndEscape("a\"bc", '\'') = 'a\"bc'
 

Parameters:

source - the source String

quoteChar - the char used to quote

Returns:

the String quoted and escaped

Since:

1.5.1

See Also:

• quoteAndEscape(String, char, char[], char[], char, boolean)

quoteAndEscape

public static String quoteAndEscape(String source,
 char quoteChar,
 char[] quotingTriggers)

Quote and escape a String with the given character, handling null.

Parameters:

source - the source String

quoteChar - the char used to quote

quotingTriggers - chars generating a quote

Returns:

the String quoted and escaped

Since:

1.5.1

See Also:

• quoteAndEscape(String, char, char[], char[], char, boolean)

quoteAndEscape

public static String quoteAndEscape(String source,
 char quoteChar,
 char[] escapedChars,
 char escapeChar,
 boolean force)

Parameters:

source - the source String

quoteChar - the char used to quote

escapedChars - chars to escape

escapeChar - char used for escaping

force - force the quoting

Returns:

the String quoted and escaped

Since:

1.5.1

See Also:

• quoteAndEscape(String, char, char[], char[], char, boolean)

quoteAndEscape

public static String quoteAndEscape(String source,
 char quoteChar,
 char[] escapedChars,
 char[] quotingTriggers,
 char escapeChar,
 boolean force)

Parameters:

source - the source String

quoteChar - the char used to quote

escapedChars - chars to escape

quotingTriggers - chars generating a quote

escapeChar - char used for escaping

force - force the quoting

Returns:

the String quoted and escaped

Since:

1.5.1

quoteAndEscape

public static String quoteAndEscape(String source,
 char quoteChar,
 char[] escapedChars,
 char[] quotingTriggers,
 String escapePattern,
 boolean force)

Parameters:

source - the source String

quoteChar - the char used to quote

escapedChars - chars to escape

quotingTriggers - chars generating a quote

escapePattern - pattern used for escaping

force - force the quoting

Returns:

the String quoted and escaped

Since:

3.0.4

escape

public static String escape(String source,
 char[] escapedChars,
 char escapeChar)

Parameters:

source - the source String

escapedChars - chars to escape

escapeChar - char used for escaping

Returns:

the String escaped

Since:

1.5.1

escape

public static String escape(String source,
 char[] escapedChars,
 String escapePattern)

Parameters:

source - the source String

escapedChars - chars to escape

escapePattern - pattern used for escaping

Returns:

the String escaped

Since:

3.0.4

removeDuplicateWhitespace

public static String removeDuplicateWhitespace(String s)

Remove all duplicate whitespace characters and line terminators are replaced with a single space.

Parameters:

s - a not null String

Returns:

a string with unique whitespace.

Since:

1.5.7

unifyLineSeparators

public static String unifyLineSeparators(String s)

Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.

Parameters:

s - a not null String

Returns:

a String that contains only System line separators.

Since:

1.5.7

See Also:

• unifyLineSeparators(String, String)

unifyLineSeparators

public static String unifyLineSeparators(String s,
 String ls)

Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.

Parameters:

s - a not null String

ls - the wanted line separator ("\n" on UNIX), if null using the System line separator.

Returns:

a String that contains only System line separators.

Throws:

IllegalArgumentException - if ls is not '\n', '\r' and '\r\n' characters.

Since:

1.5.7

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:

1.5.7

contains

public static boolean contains(String str,
 String searchStr)

Checks if String contains a search String, handling null. This method uses String.indexOf(int).

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:

1.5.7