001/* 002 * $HeadURL: file:///opt/dev/not-yet-commons-ssl-SVN-repo/tags/commons-ssl-0.3.17/src/java/org/apache/commons/ssl/util/Hex.java $ 003 * $Revision: 121 $ 004 * $Date: 2007-11-13 21:26:57 -0800 (Tue, 13 Nov 2007) $ 005 * 006 * ==================================================================== 007 * Licensed to the Apache Software Foundation (ASF) under one 008 * or more contributor license agreements. See the NOTICE file 009 * distributed with this work for additional information 010 * regarding copyright ownership. The ASF licenses this file 011 * to you under the Apache License, Version 2.0 (the 012 * "License"); you may not use this file except in compliance 013 * with the License. You may obtain a copy of the License at 014 * 015 * http://www.apache.org/licenses/LICENSE-2.0 016 * 017 * Unless required by applicable law or agreed to in writing, 018 * software distributed under the License is distributed on an 019 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 020 * KIND, either express or implied. See the License for the 021 * specific language governing permissions and limitations 022 * under the License. 023 * ==================================================================== 024 * 025 * This software consists of voluntary contributions made by many 026 * individuals on behalf of the Apache Software Foundation. For more 027 * information on the Apache Software Foundation, please see 028 * <http://www.apache.org/>. 029 * 030 */ 031 032package org.apache.commons.ssl.util; 033 034/** 035 * Utility class for dealing with hex-encoding of binary data. 036 * 037 * @author <a href="mailto:juliusdavies@cucbc.com">juliusdavies@gmail.com</a> 038 * @since 13-Nov-2007 039 */ 040public class Hex { 041 042 public static byte[] decode(String s) { 043 byte[] b = new byte[s.length() / 2]; 044 for (int i = 0; i < b.length; i++) { 045 String hex = s.substring(2 * i, 2 * (i + 1)); 046 b[i] = (byte) Integer.parseInt(hex, 16); 047 } 048 return b; 049 } 050 051 public static byte[] decode(byte[] hexString) { 052 byte[] b = new byte[hexString.length / 2]; 053 char[] chars = new char[2]; 054 for (int i = 0; i < b.length; i++) { 055 chars[0] = (char) hexString[2 * i]; 056 chars[1] = (char) hexString[2 * i + 1]; 057 String hex = new String(chars); 058 b[i] = (byte) Integer.parseInt(hex, 16); 059 } 060 return b; 061 } 062 063 public static String encode(byte[] b) { 064 return encode(b, 0, b.length); 065 } 066 067 public static String encode(byte[] b, int offset, int length) { 068 StringBuffer buf = new StringBuffer(); 069 int len = Math.min(offset + length, b.length); 070 for (int i = offset; i < len; i++) { 071 int c = (int) b[i]; 072 if (c < 0) { 073 c = c + 256; 074 } 075 if (c >= 0 && c <= 15) { 076 buf.append('0'); 077 } 078 buf.append(Integer.toHexString(c)); 079 } 080 return buf.toString(); 081 } 082 083}