Package groovy.util

Class CharsetToolkit

  • public class CharsetToolkit
extends java.lang.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​(java.io.File file)
      Constructor of the CharsetToolkit utility class.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static java.nio.charset.Charset[] getAvailableCharsets()
      Retrieves all the available Charsets on the platform, among which the default charset.
      java.nio.charset.Charset getCharset()  
      java.nio.charset.Charset getDefaultCharset()
      Retrieves the default Charset
      static java.nio.charset.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.
      java.io.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​(java.nio.charset.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​(java.io.File file)
               throws java.io.IOException
        Constructor of the CharsetToolkit utility class.
        Parameters:
        file - of which we want to know the encoding.
        Throws:
        java.io.IOException

    • Method Detail

      • setDefaultCharset

        public void setDefaultCharset​(java.nio.charset.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 java.nio.charset.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 java.nio.charset.Charset getDefaultCharset()
        Retrieves the default Charset

      • getDefaultSystemCharset

        public static java.nio.charset.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 java.io.BufferedReader getReader()
                                 throws java.io.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:
        java.io.FileNotFoundException - if the file is not found.

      • getAvailableCharsets

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