Cannot copy file with other buffer sizes, except 1

Question

Hi,
i'd like to copy files (txt, images, etc) , but by using the following route:
-read bytes from a file in a ByteBuffer
-use a byte array to create a String representation in binary form (ie "0101101") of the ByteBuffer
-print the string
and then the reverse:
-create a byte array from the String
-put the bytes in another ByteBuffer
-write them to the destination file
The problem is, that in the general case, this only works for ByteBuffer.allocate(1)! it works for txt files with any size, but not for image files; i have not tried for any other kind of file.
Ideas?
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.math.*;
/* create the copy of a file:
* In the middle print a string with the contents of the buffer, in binary form
* and then use this string to create the copy of the picture.
public class CopyFile
  static public void main( String args[] ) throws Exception
     if (args.length<2) {
      System.err.println( "Usage: java CopyFile infile outfile" );
      System.exit( 1 );
    String infile = args[0];
    String outfile = args[1];    
    FileInputStream fin = new FileInputStream( infile );
    FileOutputStream fout = new FileOutputStream( outfile );
    FileChannel fcin = fin.getChannel();
    FileChannel fcout = fout.getChannel();
    ByteBuffer bufferSource = ByteBuffer.allocate( 1 );
    ByteBuffer bufferDest = ByteBuffer.allocate( 1 );
    byte[] barraySource;
    byte[] barrayDest;
    while (true) {
      bufferSource.clear();
      int r = fcin.read( bufferSource );
      barraySource=bufferSource.array();
      BigInteger biFrom = new BigInteger(barraySource);           
      String binary = biFrom.toString(2);
      System.out.println(binary+" | ");     
       BigInteger biTo=new BigInteger(binary,2);
       barrayDest=biTo.toByteArray();
       bufferDest.clear();
       bufferDest.put(barrayDest);
      if (r==-1) {
        break;
      bufferDest.flip();
      fcout.write(bufferDest);
}

Answer 1

I've changed a couple of things, but the problem remains. It is the first time i work with binary data. Can somebody give me a hint?
public class Test2
    public static void main(String[] args) throws Exception
        File fin=new File("C:\\Documents and Settings\\p3020139\\My Documents\\pic.JPG");
        File fout=new File("C:\\Documents and Settings\\p3020139\\My Documents\\piccp.JPG");
        FileInputStream fis=new FileInputStream(fin);
        FileOutputStream fos=new FileOutputStream(fout);       
        long fileSize= fin.length();
        long bytesRead=0;
        BufferedOutputStream baos=null;
        while (bytesRead<fileSize+1)
            byte[] barray=new byte[128];
            int read=fis.read(barray); 
            BigInteger biFrom = new BigInteger(barray);           
            String binary = biFrom.toString(2);
            System.out.println(binary);
            BigInteger biTo=new BigInteger(binary,2);
            byte[] bytesTo=biTo.toByteArray();
            baos=new BufferedOutputStream(fos,128);
            baos.write(bytesTo);
            bytesRead=bytesRead+read;
        fis.close();
        baos.close();
    }