Package 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 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);
 }

  • Constructor Summary

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

  • Method Summary

    Modifier and Type Method Description
    static Charset[] getAvailableCharsets()
    Retrieves all the available Charsets 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.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • 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 Details

    • 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 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 or the default charset if an 8-bit Charset is encountered.
      Returns:
      a BufferedReader
      Throws:
      FileNotFoundException - if the file is not found.

    • getAvailableCharsets

      public static Charset[] getAvailableCharsets()
      Retrieves all the available Charsets on the platform, among which the default charset.
      Returns:
      an array of Charsets.