Package: groovy.util

## [Java] Class CharsetToolkit

- groovy.util.CharsetToolkit

- 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 used to be able to guess the encoding.

  Usage:

       CharsetToolkit toolkit = new CharsetToolkit(file);

       // guess the encoding
       Charset guessedCharset = toolkit.getCharset();

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

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

  Authors:
    Guillaume Laforge

- - ### Constructor Summary

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

  - ### Methods Summary

    Methods
    Type Params | Return Type | Name 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 or the default charset if an 8-bit `Charset` is encountered.
    `` | `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.

  - ### Inherited Methods Summary

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

- - ### Constructor Detail

    - #### public CharsetToolkit(File file)

      Constructor of the `CharsetToolkit` utility class.

      Parameters:
        `file` - of which we want to know the encoding.

  - ### Method Detail

    - #### public static Charset[] getAvailableCharsets()

      Retrieves all the available `Charset`s on the platform, among which the default `charset`.

      Returns:
        an array of `Charset`s.

    - #### public Charset getCharset()

    - #### public Charset getDefaultCharset()

      Retrieves the default Charset

    - #### public static Charset getDefaultSystemCharset()

      Retrieve the default charset of the system.

      Returns:
        the default `Charset`.

    - #### 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.

    - #### public BufferedReader getReader()

      Gets a `BufferedReader` (indeed a `LineNumberReader`) from the `File` specified in the constructor of `CharsetToolkit` using the charset discovered or the default charset if an 8-bit `Charset` is encountered.

      throws:
        FileNotFoundException if the file is not found.
      Returns:
        a `BufferedReader`

    - #### 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.

    - #### 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.

    - #### 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.

    - #### 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 if an 8-bit `Charset` is encountered.

    - #### 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.