question: public int encode ( byte [ ] data , int off , int length , OutputStream out ) throws IOException { for ( int i = off ; i < ( off + length ) ; i ++ ) { int v = data [ i ] & 0xff ; out . write ( encodingTable [ ( v > > > 4 ) ] ) ; out . write ( encodingTable [ v & 0xf ] ) ; } return length * 2 ; }
target:  encode the input data producing a Hex output stream.