Here you can find the source of toHex(byte[] bytes)
public static String toHex(byte[] bytes)
//package com.java2s; /**//from w w w.j a v a 2s.com * Copyright 2009 Red Hat, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ public class Main { public static String toHex(byte[] bytes) { return toHex(bytes, 0, bytes.length); } public static String toHex(byte[] bytes, int offset, int length) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { byte b = bytes[offset + i]; String s = Integer.toHexString(0xff & b); if (s.length() == 1) sb.append("0"); sb.append(s); } return sb.toString(); } }