libjava/gnu/gcj/convert/UnicodeToBytes.java

   1 /* Copyright (C) 1999, 2000  Red Hat, Inc.
   2
   3    This file is part of libgcj.
   4
   5 This software is copyrighted work licensed under the terms of the
   6 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   7 details.  */
   8
   9 package gnu.gcj.convert;
  10
  11 public abstract class UnicodeToBytes
  12 {
  13   /** Buffer to emit bytes to.
  14    * The locations buf[count] ... buf[buf.length-1] are available. */
  15   public byte[] buf;
  16   public int count;
  17
  18   static Class defaultEncodingClass;
  19
  20   static synchronized void getDefaultEncodingClass()
  21   {
  22     // Test (defaultEncodingClass == null) again in case of race condition.
  23     if (defaultEncodingClass == null)
  24       {
  25         String encoding = System.getProperty("file.encoding");
  26         String className = "gnu.gcj.convert.Output_"+encoding;
  27         try
  28           {
  29             defaultEncodingClass = Class.forName(className);
  30           }
  31         catch (ClassNotFoundException ex)
  32           {
  33             throw new NoClassDefFoundError("missing default encoding "
  34                                            + encoding + " (class "
  35                                            + className + " not found)");
  36
  37           }
  38       }
  39   }
  40
  41   public abstract String getName();
  42
  43   public static UnicodeToBytes getDefaultEncoder()
  44   {
  45     try
  46       {
  47         if (defaultEncodingClass == null)
  48           getDefaultEncodingClass();
  49         return (UnicodeToBytes) defaultEncodingClass.newInstance();
  50       }
  51     catch (Throwable ex)
  52       {
  53         return new Output_8859_1();
  54       }
  55   }
  56
  57   /** Get a char-stream->byte-stream converter given an encoding name. */
  58   public static UnicodeToBytes getEncoder (String encoding)
  59     throws java.io.UnsupportedEncodingException
  60   {
  61     String className = "gnu.gcj.convert.Output_"+encoding;
  62     Class encodingClass;
  63     try
  64       {
  65         encodingClass = Class.forName(className);
  66         return (UnicodeToBytes) encodingClass.newInstance();
  67       }
  68     catch (Throwable ex)
  69       {
  70         try
  71           {
  72             return new Output_iconv (encoding);
  73           }
  74         catch (Throwable _)
  75           {
  76             // Put the original exception in the throwable.
  77             throw new java.io.UnsupportedEncodingException(encoding + " ("
  78                                                            + ex + ')');
  79           }
  80       }
  81   }
  82
  83   public final void setOutput(byte[] buffer, int count)
  84   {
  85     this.buf = buffer;
  86     this.count = count;
  87   }
  88
  89   /** Convert chars to bytes.
  90     * Converted bytes are written to buf, starting at count.
  91     * @param inbuffer source of characters to convert
  92     * @param inpos index of initial character in inbuffer to convert
  93     * @param inlength number of characters to convert
  94     * @return number of chars converted
  95     * Also, this.count is increment by the number of bytes converted.
  96     */
  97   public abstract int write (char[] inbuffer, int inpos, int inlength);
  98
  99   /** Convert chars to bytes.
 100     * Converted bytes are written to buf, starting at count.
 101     * @param str source of characters to convert
 102     * @param inpos index of initial character in str to convert
 103     * @param inlength number of characters to convert
 104     * @param work if non-null, a buffer than can be used
 105     * @return number of chars converted
 106     * Also, this.count is increment by the number of bytes converted.
 107     */
 108   public int write (String str, int inpos, int inlength, char[] work)
 109   {
 110     if (work == null)
 111       work = new char[inlength];
 112     int srcEnd = inpos + (inlength > work.length ? work.length : inlength);
 113     str.getChars(inpos, srcEnd, work, 0);
 114     return write(work, inpos, inlength);
 115   }
 116 }