Here you can find the source of toByteArray(String string)
private static byte[] toByteArray(String string)
//package com.java2s; /*//from w w w . j a v a2s.c om * Copyright (c) 2015 Nikolay Zapolnov (zapolnov@gmail.com). * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ public class Main { private static byte[] toByteArray(String string) { int count = string.length() / 2; byte[] result = new byte[count]; for (int i = 0; i < count; i++) { char c1 = string.charAt(i * 2); char c2 = string.charAt(i * 2 + 1); result[i] = (byte) ((unhex(c1) << 4) | unhex(c2)); } return result; } private static int unhex(char c) { if (c >= '0' && c <= '9') return c - '0'; if (c >= 'a' && c <= 'f') return c - 'a' + 10; if (c >= 'A' && c <= 'F') return c - 'A' + 10; throw new RuntimeException(String.format("Invalid hexadecimal digit '%c'.", c)); } }