Java tutorial
//package com.java2s; public class Main { public static String bytes2Bits(byte[] bytes) { StringBuilder sb = new StringBuilder(); for (byte aByte : bytes) { for (int j = 7; j >= 0; --j) { sb.append(((aByte >> j) & 0x01) == 0 ? '0' : '1'); } } return sb.toString(); } }