org.apache.commons.lang
Class WordUtils

java.lang.Object
  org.apache.commons.lang.WordUtils

public class WordUtils
extends Object

Operations on Strings that contain words.

This class tries to handle null input gracefully. An exception will not be thrown for a null input. Each method documents its behaviour in more detail.

Since:

2.0

Version:

$Id: WordUtils.java 905636 2010-02-02 14:03:32Z niallp $

Author:

Apache Jakarta Velocity, Apache Software Foundation, Henning P. Schmiedehausen, Gary Gregory

Constructor Summary

WordUtils()
WordUtils instances should NOT be constructed in standard programming.

Method Summary

static String	abbreviate(String str, int lower, int upper, String appendToEnd) Abbreviates a string nicely.
static String	capitalize(String str) Capitalizes all the whitespace separated words in a String.
static String	capitalize(String str, char[] delimiters) Capitalizes all the delimiter separated words in a String.
static String	capitalizeFully(String str) Converts all the whitespace separated words in a String into capitalized words, that is each word is made up of a titlecase character and then a series of lowercase characters.
static String	capitalizeFully(String str, char[] delimiters) Converts all the delimiter separated words in a String into capitalized words, that is each word is made up of a titlecase character and then a series of lowercase characters.
static String	initials(String str) Extracts the initial letters from each word in the String.
static String	initials(String str, char[] delimiters) Extracts the initial letters from each word in the String.
static String	swapCase(String str) Swaps the case of a String using a word based algorithm.
static String	uncapitalize(String str) Uncapitalizes all the whitespace separated words in a String.
static String	uncapitalize(String str, char[] delimiters) Uncapitalizes all the whitespace separated words in a String.
static String	wrap(String str, int wrapLength) Wraps a single line of text, identifying words by ' '.
static String	wrap(String str, int wrapLength, String newLineStr, boolean wrapLongWords) Wraps a single line of text, identifying words by ' '.

Methods inherited from class java.lang.Object

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

Constructor Detail

WordUtils

public WordUtils()

WordUtils instances should NOT be constructed in standard programming. Instead, the class should be used as WordUtils.wrap("foo bar", 20);.

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Detail

wrap

public static String wrap(String str,
                          int wrapLength)

Wraps a single line of text, identifying words by ' '.

New lines will be separated by the system property line separator. Very long words, such as URLs will not be wrapped.

Leading spaces on a new line are stripped. Trailing spaces are not stripped.

 WordUtils.wrap(null, *) = null
 WordUtils.wrap("", *) = ""
 

Parameters:

str - the String to be word wrapped, may be null

wrapLength - the column to wrap the words at, less than 1 is treated as 1

Returns:

a line with newlines inserted, null if null input

wrap

public static String wrap(String str,
                          int wrapLength,
                          String newLineStr,
                          boolean wrapLongWords)

Wraps a single line of text, identifying words by ' '.

Leading spaces on a new line are stripped. Trailing spaces are not stripped.

 WordUtils.wrap(null, *, *, *) = null
 WordUtils.wrap("", *, *, *) = ""
 

Parameters:

str - the String to be word wrapped, may be null

wrapLength - the column to wrap the words at, less than 1 is treated as 1

newLineStr - the string to insert for a new line, null uses the system property line separator

wrapLongWords - true if long words (such as URLs) should be wrapped

Returns:

a line with newlines inserted, null if null input

capitalize

public static String capitalize(String str)

Capitalizes all the whitespace separated words in a String. Only the first letter of each word is changed. To convert the rest of each word to lowercase at the same time, use capitalizeFully(String).

Whitespace is defined by Character.isWhitespace(char). A null input String returns null. Capitalization uses the unicode title case, normally equivalent to upper case.

 WordUtils.capitalize(null)        = null
 WordUtils.capitalize("")          = ""
 WordUtils.capitalize("i am FINE") = "I Am FINE"
 

Parameters:

str - the String to capitalize, may be null

Returns:

capitalized String, null if null String input

See Also:

uncapitalize(String), capitalizeFully(String)

capitalize

public static String capitalize(String str,
                                char[] delimiters)

Capitalizes all the delimiter separated words in a String. Only the first letter of each word is changed. To convert the rest of each word to lowercase at the same time, use capitalizeFully(String, char[]).

The delimiters represent a set of characters understood to separate words. The first string character and the first non-delimiter character after a delimiter will be capitalized.

A null input String returns null. Capitalization uses the unicode title case, normally equivalent to upper case.

 WordUtils.capitalize(null, *)            = null
 WordUtils.capitalize("", *)              = ""
 WordUtils.capitalize(*, new char[0])     = *
 WordUtils.capitalize("i am fine", null)  = "I Am Fine"
 WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
 

Parameters:

str - the String to capitalize, may be null

delimiters - set of characters to determine capitalization, null means whitespace

Returns:

capitalized String, null if null String input

Since:

2.1

See Also:

uncapitalize(String), capitalizeFully(String)

capitalizeFully

public static String capitalizeFully(String str)

Converts all the whitespace separated words in a String into capitalized words, that is each word is made up of a titlecase character and then a series of lowercase characters.

Whitespace is defined by Character.isWhitespace(char). A null input String returns null. Capitalization uses the unicode title case, normally equivalent to upper case.

 WordUtils.capitalizeFully(null)        = null
 WordUtils.capitalizeFully("")          = ""
 WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
 

Parameters:

str - the String to capitalize, may be null

Returns:

capitalized String, null if null String input

capitalizeFully

public static String capitalizeFully(String str,
                                     char[] delimiters)

Converts all the delimiter separated words in a String into capitalized words, that is each word is made up of a titlecase character and then a series of lowercase characters.

The delimiters represent a set of characters understood to separate words. The first string character and the first non-delimiter character after a delimiter will be capitalized.

A null input String returns null. Capitalization uses the unicode title case, normally equivalent to upper case.

 WordUtils.capitalizeFully(null, *)            = null
 WordUtils.capitalizeFully("", *)              = ""
 WordUtils.capitalizeFully(*, null)            = *
 WordUtils.capitalizeFully(*, new char[0])     = *
 WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
 

Parameters:

str - the String to capitalize, may be null

delimiters - set of characters to determine capitalization, null means whitespace

Returns:

capitalized String, null if null String input

Since:

2.1

uncapitalize

public static String uncapitalize(String str)

Uncapitalizes 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.

 WordUtils.uncapitalize(null)        = null
 WordUtils.uncapitalize("")          = ""
 WordUtils.uncapitalize("I Am FINE") = "i am fINE"
 

Parameters:

str - the String to uncapitalize, may be null

Returns:

uncapitalized String, null if null String input

See Also:

capitalize(String)

uncapitalize

public static String uncapitalize(String str,
                                  char[] delimiters)

Uncapitalizes all the whitespace separated words in a String. Only the first letter of each word is changed.

The delimiters represent a set of characters understood to separate words. The first string character and the first non-delimiter character after a delimiter will be uncapitalized.

Whitespace is defined by Character.isWhitespace(char). A null input String returns null.

 WordUtils.uncapitalize(null, *)            = null
 WordUtils.uncapitalize("", *)              = ""
 WordUtils.uncapitalize(*, null)            = *
 WordUtils.uncapitalize(*, new char[0])     = *
 WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
 

Parameters:

str - the String to uncapitalize, may be null

delimiters - set of characters to determine uncapitalization, null means whitespace

Returns:

uncapitalized String, null if null String input

Since:

2.1

See Also:

capitalize(String)

swapCase

public static String swapCase(String str)

Swaps the case of a String using a word based algorithm.

• Upper case character converts to Lower case
• Title case character converts to Lower case
• Lower case character after Whitespace or at start converts to Title case
• Other Lower case character converts to Upper case

Whitespace is defined by Character.isWhitespace(char). A null input String returns null.

 StringUtils.swapCase(null)                 = null
 StringUtils.swapCase("")                   = ""
 StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
 

Parameters:

str - the String to swap case, may be null

Returns:

the changed String, null if null String input

initials

public static String initials(String str)

Extracts the initial letters from each word in the String.

The first letter of the string and all first letters after whitespace are returned as a new string. Their case is not changed.

Whitespace is defined by Character.isWhitespace(char). A null input String returns null.

 WordUtils.initials(null)             = null
 WordUtils.initials("")               = ""
 WordUtils.initials("Ben John Lee")   = "BJL"
 WordUtils.initials("Ben J.Lee")      = "BJ"
 

Parameters:

str - the String to get initials from, may be null

Returns:

String of initial letters, null if null String input

Since:

2.2

See Also:

initials(String,char[])

initials

public static String initials(String str,
                              char[] delimiters)

Extracts the initial letters from each word in the String.

The first letter of the string and all first letters after the defined delimiters are returned as a new string. Their case is not changed.

If the delimiters array is null, then Whitespace is used. Whitespace is defined by Character.isWhitespace(char). A null input String returns null. An empty delimiter array returns an empty String.

 WordUtils.initials(null, *)                = null
 WordUtils.initials("", *)                  = ""
 WordUtils.initials("Ben John Lee", null)   = "BJL"
 WordUtils.initials("Ben J.Lee", null)      = "BJ"
 WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
 WordUtils.initials(*, new char[0])         = ""
 

Parameters:

str - the String to get initials from, may be null

delimiters - set of characters to determine words, null means whitespace

Returns:

String of initial letters, null if null String input

Since:

2.2

See Also:

initials(String)

abbreviate

public static String abbreviate(String str,
                                int lower,
                                int upper,
                                String appendToEnd)

Abbreviates a string nicely. This method searches for the first space after the lower limit and abbreviates the String there. It will also append any String passed as a parameter to the end of the String. The upper limit can be specified to forcibly abbreviate a String.

Parameters:

str - the string to be abbreviated. If null is passed, null is returned. If the empty String is passed, the empty string is returned.

lower - the lower limit.

upper - the upper limit; specify -1 if no limit is desired. If the upper limit is lower than the lower limit, it will be adjusted to be the same as the lower limit.

appendToEnd - String to be appended to the end of the abbreviated string. This is appended ONLY if the string was indeed abbreviated. The append does not count towards the lower or upper limits.

Returns:

the abbreviated String.

Since:

2.4