Here you can find the source of arrayCopy(byte[] dest, int offset, byte[] in)
static public void arrayCopy(byte[] dest, int offset, byte[] in)
//package com.java2s; //License from project: Open Source License public class Main { static public void arrayCopy(byte[] dest, int offset, byte[] in) { System.arraycopy(in, 0, dest, offset, in.length); }//from w ww . j a v a2s . c om }