groovy.util

## Class CharsetToolkit

- java.lang.Object
- - groovy.util.CharsetToolkit

-     public class CharsetToolkit
      extends Object

  Utility class to guess the encoding of a given text file.

  Unicode files encoded in UTF-16 (low or big endian) or UTF-8 files with a Byte Order Marker are correctly discovered. For UTF-8 files with no BOM, if the buffer is wide enough, the charset should also be discovered.

  A byte buffer of 4KB is usually sufficient to be able to guess the encoding.

  Usage:

       // guess the encoding
       Charset guessedCharset = CharsetToolkit.guessEncoding(file, 4096);

       // create a reader with the correct charset
       CharsetToolkit toolkit = new CharsetToolkit(file);
       BufferedReader reader = toolkit.getReader();

       // read the file content
       String line;
       while ((line = br.readLine())!= null)
       {
           System.out.println(line);
       }

  Author:
    Guillaume Laforge

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `CharsetToolkit(File file)` Constructor of the `CharsetToolkit` utility class.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static Charset[]` | `getAvailableCharsets()` Retrieves all the available `Charset`s on the platform, among which the default `charset`.
    `Charset` | `getCharset()`
    `Charset` | `getDefaultCharset()` Retrieves the default Charset
    `static Charset` | `getDefaultSystemCharset()` Retrieve the default charset of the system.
    `boolean` | `getEnforce8Bit()` Gets the enforce8Bit flag, in case we do not want to ever get a US-ASCII encoding.
    `BufferedReader` | `getReader()` Gets a `BufferedReader` (indeed a `LineNumberReader`) from the `File` specified in the constructor of `CharsetToolkit` using the charset discovered by the method `guessEncoding()`.
    `boolean` | `hasUTF16BEBom()` Has a Byte Order Marker for UTF-16 Big Endian (utf-16 and ucs-2).
    `boolean` | `hasUTF16LEBom()` Has a Byte Order Marker for UTF-16 Low Endian (ucs-2le, ucs-4le, and ucs-16le).
    `boolean` | `hasUTF8Bom()` Has a Byte Order Marker for UTF-8 (Used by Microsoft's Notepad and other editors).
    `void` | `setDefaultCharset(Charset defaultCharset)` Defines the default `Charset` used in case the buffer represents an 8-bit `Charset`.
    `void` | `setEnforce8Bit(boolean enforce)` If US-ASCII is recognized, enforce to return the default encoding, rather than US-ASCII.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### CharsetToolkit

          public CharsetToolkit(File file)
                         throws IOException

      Constructor of the `CharsetToolkit` utility class.
      Parameters:
        `file` - of which we want to know the encoding.
      Throws:
        `IOException`

  - ### Method Detail

    - #### setDefaultCharset

          public void setDefaultCharset(Charset defaultCharset)

      Defines the default `Charset` used in case the buffer represents an 8-bit `Charset`.
      Parameters:
        `defaultCharset` - the default `Charset` to be returned by `guessEncoding()` if an 8-bit `Charset` is encountered.

    - #### getCharset

          public Charset getCharset()

    - #### setEnforce8Bit

          public void setEnforce8Bit(boolean enforce)

      If US-ASCII is recognized, enforce to return the default encoding, rather than US-ASCII. It might be a file without any special character in the range 128-255, but that may be or become a file encoded with the default `charset` rather than US-ASCII.
      Parameters:
        `enforce` - a boolean specifying the use or not of US-ASCII.

    - #### getEnforce8Bit

          public boolean getEnforce8Bit()

      Gets the enforce8Bit flag, in case we do not want to ever get a US-ASCII encoding.
      Returns:
        a boolean representing the flag of use of US-ASCII.

    - #### getDefaultCharset

          public Charset getDefaultCharset()

      Retrieves the default Charset

    - #### getDefaultSystemCharset

          public static Charset getDefaultSystemCharset()

      Retrieve the default charset of the system.
      Returns:
        the default `Charset`.

    - #### hasUTF8Bom

          public boolean hasUTF8Bom()

      Has a Byte Order Marker for UTF-8 (Used by Microsoft's Notepad and other editors).
      Returns:
        true if the buffer has a BOM for UTF8.

    - #### hasUTF16LEBom

          public boolean hasUTF16LEBom()

      Has a Byte Order Marker for UTF-16 Low Endian (ucs-2le, ucs-4le, and ucs-16le).
      Returns:
        true if the buffer has a BOM for UTF-16 Low Endian.

    - #### hasUTF16BEBom

          public boolean hasUTF16BEBom()

      Has a Byte Order Marker for UTF-16 Big Endian (utf-16 and ucs-2).
      Returns:
        true if the buffer has a BOM for UTF-16 Big Endian.

    - #### getReader

          public BufferedReader getReader()
                                   throws FileNotFoundException

      Gets a `BufferedReader` (indeed a `LineNumberReader`) from the `File` specified in the constructor of `CharsetToolkit` using the charset discovered by the method `guessEncoding()`.
      Returns:
        a `BufferedReader`
      Throws:
        `FileNotFoundException` - if the file is not found.

    - #### getAvailableCharsets

          public static Charset[] getAvailableCharsets()

      Retrieves all the available `Charset`s on the platform, among which the default `charset`.
      Returns:
        an array of `Charset`s.