gomp-20050608-branch/libjava/gnu/gcj/convert/BytesToCharsetAdaptor.java

   1 /* Copyright (C) 2005  Free Software Foundation
   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 import java.nio.ByteBuffer;
  12 import java.nio.CharBuffer;
  13 import java.nio.charset.Charset;
  14 import java.nio.charset.CharsetDecoder;
  15 import java.nio.charset.CodingErrorAction;
  16 import java.nio.charset.CoderResult;
  17 import gnu.java.nio.charset.EncodingHelper;
  18
  19 /**
  20  * Adaptor class that allow any {@link Charset} to be used
  21  * as a BytesToUnicode converter.
  22  */
  23 public class BytesToCharsetAdaptor extends BytesToUnicode
  24 {
  25   /**
  26    * The CharsetDecoder that does all the work.
  27    */
  28   private final CharsetDecoder decoder;
  29
  30   /**
  31    * ByteBuffer wrapper for this.buf.
  32    */
  33   private ByteBuffer inBuf;
  34
  35   /**
  36    * Create a new BytesToCharsetAdaptor for the given Charset.
  37    *
  38    * @param cs the Charset.
  39    */
  40   public BytesToCharsetAdaptor(Charset cs)
  41   {
  42     this(cs.newDecoder());
  43   }
  44
  45   /**
  46    * Create a new BytesToCharsetAdaptor for the given CharsetDecoder.
  47    *
  48    * @param dec the CharsetDecoder.
  49    */
  50   public BytesToCharsetAdaptor(CharsetDecoder dec)
  51   {
  52     decoder = dec;
  53     // Use default replacments on bad input so that we don't have to
  54     // deal with errors.
  55     decoder.onMalformedInput(CodingErrorAction.REPLACE);
  56     decoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
  57   }
  58
  59   /**
  60    * Return the decoder's name.  The backing Charset's name is
  61    * returned.
  62    *
  63    * @return The name.
  64    */
  65   public String getName()
  66   {
  67     return EncodingHelper.getOldCanonical(decoder.charset().name());
  68   }
  69
  70   public int read(char[] outbuffer, int outpos, int count)
  71   {
  72     if (inBuf == null || ! inBuf.hasArray() || inBuf.array() != inbuffer)
  73       inBuf = ByteBuffer.wrap(inbuffer);
  74     inBuf.limit(inpos + inlength);
  75     inBuf.position(inpos);
  76
  77     CharBuffer outBuf = CharBuffer.wrap(outbuffer, outpos, count);
  78     decoder.decode(inBuf, outBuf, false);
  79
  80     // Update this.inpos to reflect the bytes consumed.
  81     inpos = inBuf.position();
  82     // Return the number of characters that were written to outbuffer.
  83     return outBuf.position() - outpos;
  84   }
  85
  86   // These aren't cached.
  87   public void done()
  88   {
  89   }
  90 }