| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tomcat.util.buf; |
| |
| import org.apache.tomcat.util.res.StringManager; |
| |
| /** |
| * Tables useful when converting byte arrays to and from strings of hexadecimal |
| * digits. |
| * Code from Ajp11, from Apache's JServ. |
| * |
| * @author Craig R. McClanahan |
| */ |
| public final class HexUtils { |
| |
| private static final StringManager sm = |
| StringManager.getManager(Constants.Package); |
| |
| // -------------------------------------------------------------- Constants |
| |
| /** |
| * Table for HEX to DEC byte translation. |
| */ |
| private static final int[] DEC = { |
| 00, 01, 02, 03, 04, 05, 06, 07, 8, 9, -1, -1, -1, -1, -1, -1, |
| -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| -1, 10, 11, 12, 13, 14, 15, |
| }; |
| |
| |
| /** |
| * Table for DEC to HEX byte translation. |
| */ |
| private static final byte[] HEX = |
| { (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', |
| (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'a', (byte) 'b', |
| (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f' }; |
| |
| |
| /** |
| * Table for byte to hex string translation. |
| */ |
| private static final char[] hex = "0123456789abcdef".toCharArray(); |
| |
| |
| // --------------------------------------------------------- Static Methods |
| |
| public static int getDec(int index) { |
| // Fast for correct values, slower for incorrect ones |
| try { |
| return DEC[index - '0']; |
| } catch (ArrayIndexOutOfBoundsException ex) { |
| return -1; |
| } |
| } |
| |
| |
| public static byte getHex(int index) { |
| return HEX[index]; |
| } |
| |
| |
| public static String toHexString(byte[] bytes) { |
| if (null == bytes) { |
| return null; |
| } |
| |
| StringBuilder sb = new StringBuilder(bytes.length << 1); |
| |
| for(int i = 0; i < bytes.length; ++i) { |
| sb.append(hex[(bytes[i] & 0xf0) >> 4]) |
| .append(hex[(bytes[i] & 0x0f)]) |
| ; |
| } |
| |
| return sb.toString(); |
| } |
| |
| |
| public static byte[] fromHexString(String input) { |
| if (input == null) { |
| return null; |
| } |
| |
| if ((input.length() & 1) == 1) { |
| // Odd number of characters |
| throw new IllegalArgumentException(sm.getString("hexUtils.fromHex.oddDigits")); |
| } |
| |
| char[] inputChars = input.toCharArray(); |
| byte[] result = new byte[input.length() >> 1]; |
| for (int i = 0; i < result.length; i++) { |
| int upperNibble = getDec(inputChars[2*i]); |
| int lowerNibble = getDec(inputChars[2*i + 1]); |
| if (upperNibble < 0 || lowerNibble < 0) { |
| // Non hex character |
| throw new IllegalArgumentException(sm.getString("hexUtils.fromHex.nonHex")); |
| } |
| result[i] = (byte) ((upperNibble << 4) + lowerNibble); |
| } |
| return result; |
| } |
| } |