org.apache.commons.lang3.text

## Class WordUtils

- java.lang.Object
- - org.apache.commons.lang3.text.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 1583482 2014-03-31 22:54:57Z niallp $

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `WordUtils()` `WordUtils` instances should NOT be constructed in standard programming.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `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.

      input | wrapLength | result
      --- | --- | ---
      null | * | null
      "" | * | ""
      "Here is one line of text that is going to be wrapped after 20 columns." | 20 | "Here is one line of\ntext that is going\nto be wrapped after\n20 columns."
      "Click here to jump to the commons website - http://commons.apache.org" | 20 | "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"
      "Click here, http://commons.apache.org, to jump to the commons website" | 20 | "Click here,\nhttp://commons.apache.org,\nto jump to the\ncommons website"

      (assuming that '\n' is the systems line separator)
      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.

      input | wrapLenght | newLineString | wrapLongWords | result
      --- | --- | --- | --- | ---
      null | * | * | true/false | null
      "" | * | * | true/false | ""
      "Here is one line of text that is going to be wrapped after 20 columns." | 20 | "\n" | true/false | "Here is one line of\ntext that is going\nto be wrapped after\n20 columns."
      "Here is one line of text that is going to be wrapped after 20 columns." | 20 | "<br />" | true/false | "Here is one line of<br />text that is going<br />to be wrapped after<br />20 columns."
      "Here is one line of text that is going to be wrapped after 20 columns." | 20 | null | true/false | "Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."
      "Click here to jump to the commons website - http://commons.apache.org" | 20 | "\n" | false | "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"
      "Click here to jump to the commons website - http://commons.apache.org" | 20 | "\n" | true | "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apach\ne.org"

      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)`

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