public static  void flow(Reader reader,
    Writer writer) throws IOException 
{
        char[] buf = new char[DEFAULT_BUFFER_SIZE];
        flow( reader, writer, buf );
}

 public static  void flow(InputStream is,
    OutputStream os) throws IOException 
{
        byte[] buf = new byte[DEFAULT_BUFFER_SIZE];
        flow( is, os, buf );
}

 public static  void flow(Reader reader,
    Writer writer,
    char[] buf) throws IOException 
{
        int numRead;
        while ( (numRead = reader.read(buf) )  >= 0) {
            writer.write(buf, 0, numRead);
        }
}

Read input from reader and write it to writer until there is no more input from reader.

 public static  void flow(InputStream is,
    OutputStream os,
    byte[] buf) throws IOException 
{
        int numRead;
        while ( (numRead = is.read(buf) )  >= 0) {
            os.write(buf, 0, numRead);
        }
}

Read input from input stream and write it to output stream until there is no more input from input stream.