Package: groovy.json

## [Java] Class StringEscapeUtils

- groovy.json.StringEscapeUtils

-     public class StringEscapeUtils
      extends Object

  Escapes and unescapes `String`s for Java, Java Script, HTML, XML, and SQL.

  #ThreadSafe#

  Note that this version is a stripped down version from Commons Lang 2.6 with only necessary methods for JSON builder

  Authors:
    Apache Software Foundation
    Apache Jakarta Turbine
    Purple Technology
    Alexander Day Chaffee
    Antony Riley
    Helge Tesgaard
    Sean Brown
    Gary Gregory
    Phil Steitz
    Pete Gieser
  Since:
    2.0

- - ### Constructor Summary

    Constructors
    Constructor and description
    `StringEscapeUtils()`

  - ### Methods Summary

    Methods
    Type Params | Return Type | Name and description
    --- | --- | ---
    `` | `public static String` | `escapeJava(String str)` Escapes the characters in a `String` using Java String rules.
    `` | `public static void` | `escapeJava(Writer out, String str)` Escapes the characters in a `String` using Java String rules to a `Writer`.
    `` | `public static String` | `escapeJavaScript(String str)` Escapes the characters in a `String` using JavaScript String rules.
    `` | `public static void` | `escapeJavaScript(Writer out, String str)` Escapes the characters in a `String` using JavaScript String rules to a `Writer`.
    `` | `public static String` | `unescapeJava(String str)` Unescapes any Java literals found in the `String`.
    `` | `public static void` | `unescapeJava(Writer out, String str)`
    `` | `public static String` | `unescapeJavaScript(String str)` Unescapes any JavaScript literals found in the `String`.
    `` | `public static void` | `unescapeJavaScript(Writer out, String str)` Unescapes any JavaScript literals found in the `String` to a `Writer`.

  - ### Inherited Methods Summary

    Inherited Methods
    Methods inherited from class | Name
    --- | ---
    `class Object` | `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### public StringEscapeUtils()

      `StringEscapeUtils` instances should NOT be constructed in standard programming.

      Instead, the class should be used as:

          StringEscapeUtils.escapeJava("foo");

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

  - ### Method Detail

    - #### public static String escapeJava(String str)

      Escapes the characters in a `String` using Java String rules.

      Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

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

      The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote must be escaped.

      Example:

           input string: They didn't say, "Stop!"
           output string: They didn't say, \"Stop!\"

      Parameters:
        `str` - String to escape values in, may be null
      Returns:
        String with escaped values, `null` if null string input

    - #### public static void escapeJava(Writer out, String str)

      Escapes the characters in a `String` using Java String rules to a `Writer`.

      A `null` string input has no effect.

      throws:
        IllegalArgumentException if the Writer is `null`
      throws:
        IOException if error occurs on underlying Writer
      See Also:
        escapeJava(java.lang.String)
      Parameters:
        `out` - Writer to write escaped string into
        `str` - String to escape values in, may be null

    - #### public static String escapeJavaScript(String str)

      Escapes the characters in a `String` using JavaScript String rules.

      Escapes any values it finds into their JavaScript String form. Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)

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

      The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote must be escaped.

      Example:

           input string: They didn't say, "Stop!"
           output string: They didn\'t say, \"Stop!\"

      Parameters:
        `str` - String to escape values in, may be null
      Returns:
        String with escaped values, `null` if null string input

    - #### public static void escapeJavaScript(Writer out, String str)

      Escapes the characters in a `String` using JavaScript String rules to a `Writer`.

      A `null` string input has no effect.

      throws:
        IllegalArgumentException if the Writer is `null`
      throws:
        IOException if error occurs on underlying Writer
      See Also:
        escapeJavaScript(java.lang.String)
      Parameters:
        `out` - Writer to write escaped string into
        `str` - String to escape values in, may be null

    - #### public static String unescapeJava(String str)

      Unescapes any Java literals found in the `String`. For example, it will turn a sequence of `'\'` and `'n'` into a newline character, unless the `'\'` is preceded by another `'\'`.

      throws:
        JsonException if a `'\\u'` escape is not followed by four hexadecimal digits
      Parameters:
        `str` - the `String` to unescape, may be null
      Returns:
        a new unescaped `String`, `null` if null string input

    - #### public static void unescapeJava(Writer out, String str)

      Unescapes any Java literals found in the `String` to a `Writer`.

      For example, it will turn a sequence of `'\'` and `'n'` into a newline character, unless the `'\'` is preceded by another `'\'`.

      A `null` string input has no effect.

      throws:
        IllegalArgumentException if the Writer is `null`
      throws:
        IOException if error occurs on underlying Writer
      throws:
        JsonException if a `'\\u'` escape is not followed by four hexadecimal digits
      Parameters:
        `out` - the `Writer` used to output unescaped characters
        `str` - the `String` to unescape, may be null

    - #### public static String unescapeJavaScript(String str)

      Unescapes any JavaScript literals found in the `String`.

      For example, it will turn a sequence of `'\'` and `'n'` into a newline character, unless the `'\'` is preceded by another `'\'`.

      See Also:
        unescapeJava(String)
      Parameters:
        `str` - the `String` to unescape, may be null
      Returns:
        A new unescaped `String`, `null` if null string input

    - #### public static void unescapeJavaScript(Writer out, String str)

      Unescapes any JavaScript literals found in the `String` to a `Writer`.

      For example, it will turn a sequence of `'\'` and `'n'` into a newline character, unless the `'\'` is preceded by another `'\'`.

      A `null` string input has no effect.

      throws:
        IllegalArgumentException if the Writer is `null`
      throws:
        IOException if error occurs on underlying Writer
      See Also:
        unescapeJava(Writer,String)
      Parameters:
        `out` - the `Writer` used to output unescaped characters
        `str` - the `String` to unescape, may be null