Character Sets - socketchannel read error

Question

I have made an FTPserver which i have just noticed is having trouble when the file name being requested/send has non-ASCII characters in it such as '�'.
Since i am using nio i thought it would just be an simple task of just changing the character set from "US-ASCII" to "UTF-8" or "UTF-16".
but when i changed it to UTF-8 there was no change, that is i still recieve an error:
java.nio.charset.MalformedInputException: Input length = 1
java.nio.charset.CoderResult.throwException(CoderResult.java:260)
java.nio.charset.CharsetDecoder.decode(CharsetDecoder.java:763)
Worker.readCommand(Worker.java:282)
Worker.handleClient(Worker.java:562)
Worker.run(Worker.java:144)
java.lang.Thread.run(Thread.java:536)
And when i tried UTF-16 no input was ever detected by my server...
This 'input length = 1' business... does this mean that there must be more than one byte in the recieved byte array or am i going off on a incorrect tangent?
Any suggestions or theories would be listened to!
Cheers
(btw i will not be able to reply to this post for another 11 hrs)

Answer 1

I can but it will not be of much use as it is more a logical error or a misunderstanding of how to use the character set.
well here is the relevant code anyway:
// readCommand: waits until a command is recieved from the client and then returns the command
       String readCommand(InputStream is, PrintStream ps) throws java.io.IOException
         int nread = 0, r = 0;
         String str="";
         Charset charset = Charset.forName("UTF-8");
         CharsetDecoder decoder = charset.newDecoder();
      // Direct byte buffer for reading
         ByteBuffer dbuf = ByteBuffer.allocateDirect(1024);
//      outerloop:
         do
            dbuf.clear();
            boolean quit=false;
            String message="";
            int bytesRead=0;
// while there is no input in the buffer            
            while (dbuf.position()==0)
// read in any bytes that are waiting into the buffer
               sc.configureBlocking(false);
               bytesRead=sc.read(dbuf);
               sc.configureBlocking(true);
// wait for two milliseconds before trying to read again
               try
                  wait(2);
                   catch (InterruptedException e)
// if the client has not yet finished the connection negoiation see if the client has been connected for more than 30 seconds, if so disconnect the client
               if (account==-1)
                  if (System.currentTimeMillis()>clientStartTime+30000)
                     quit=true;
               else
// if the thread has been told to quit the connection set the quit flag
                  if (exitThread)
                       message="421 Quitting...";
                       quit=true;
// If there is a sessionlimit see if the connection has exceeded the limit, if so set the quit flag
                  if (staticSessionLimit[account]>0)
                     if (System.currentTimeMillis()>clientStartTime+staticSessionLimit[account])
                        message="421 Session Limit Exceeded... please re-connect in 30 seconds";
                        quit=true;
// if there is an inactivity timout see if the client has not been active for more than the timeout, if so set the quit flag
                  if (staticInactivityTimeout[account]>0)
                     if (System.currentTimeMillis()>lastActiveTime+staticInactivityTimeout[account])
                        message="421 Inactivity Timeout Exceeded... closing connection";
                        quit=true;
// if the quit flag is set return "QUIT" which tells the thread to close the connection and return to the pool
               if (quit)
                  ps.print(message);
                  ps.write(EOL);
                  ps.flush();
                  return "QUIT";
            dbuf.flip();
               CharBuffer cb=null;
// if there are bytes in the buffer, add the data to the recieved command string (str)
               if (bytesRead>=0)
                    cb = decoder.decode(dbuf);
                      str=str+cb.toString();
// repeat while EOL is not detected
         } while (str.length()<2 || !str.substring(str.length()-2).equals("\r\n"));
         str=str.substring(0,str.length()-2);
         FTPServer.log("STRING: "+str);
         lastActiveTime=System.currentTimeMillis();
// update the last action requested by the client in the governor
         governor.addAction(str,this);
         return str;
      }