Converting from CP1252 (Windows) to ISO 8859-1 doesn't work with java.nio?

Question

Hi
I'm trying to write some code that checks whether an InputStream contains only characters with a given encoding. I'm using java.nio for that. For tests, I downloaded some character set examples from http://www.columbia.edu/kermit/csettables.html
When creating the CharsetDecoder, I want to get all errors:
    Charset charset = Charset.forName( encoding );
    CharsetDecoder decoder = charset.newDecoder();
    decoder.onMalformedInput( CodingErrorAction.REPORT );
    decoder.onUnmappableCharacter( CodingErrorAction.REPORT );I then read an InputStream and try to convert it. If that fails, it can't contain the desired encoding:
    boolean isWellEncoded = true;
    ByteBuffer inBuffer = ByteBuffer.allocate( 1024 );
    ReadableByteChannel channel = Channels.newChannel( inputStream );
    while ( channel.read( inBuffer ) != -1 )
      CharBuffer decoded = null;
      try
        inBuffer.flip();
        decoded = decoder.decode( inBuffer );
      catch ( MalformedInputException ex )
        isWellEncoded = false;
      catch ( UnmappableCharacterException ex )
        isWellEncoded = false;
      catch ( CharacterCodingException ex )
        isWellEncoded = false;
      if ( decoded != null )
        LOG.debug( decoded.toString() );
      if ( !isWellEncoded )
        break;
      inBuffer.compact();
    channel.close();
    return isWellEncoded;Now I want to check whether a file containing Windows 1252 characters is ISO-8859-1. From my point of view, the code above should fail when it gets to the Euro symbol (decimal 128), since that's not defined in ISO-8859-1.
But all I get is a ? character instead:
(})  125  07/13  175  7D                 RIGHT CURLY BRACKET, RIGHT BRACE
(~)  126  07/14  176  7E                 TILDE
[?]  128  08/00  200  80  EURO SYMBOL
[?]  130  08/02  202  82  LOW 9 SINGLE QUOTEI also tried to replace the faulty character, using
    decoder.onUnmappableCharacter( CodingErrorAction.REPLACE );
    decoder.replaceWith("!");but I still get the question marks.
I'm probably doing something fundamentally wrong, but I dont get it :-)
Any help is greatly appreciated!
Eric

Answer 1

As a suggestion....create a complete example demonstrating the problem. It shouldn't have channel in it since that wouldn't appear to be the problem (decoding is.) You should create the byte array in the example code - populate it with the byte sequence that you think should work. And your code should then demonstrate that it doesn't. Then post that.