question: public static void writeSingleByte ( OutputStream out , int b ) throws IOException { byte [ ] buffer = new byte [ 1 ] ; buffer [ 0 ] = ( byte ) ( b & 0xff ) ; out . write ( buffer ) ; }
target:  Implements OutputStream.write(int) in terms of OutputStream.write(byte[], int, int). OutputStream assumes that you implement OutputStream.write(int) and provides default implementations of the others, but often the opposite is more efficient.