001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.util;
018    
019    /**
020     * Used to convert to hex from byte arrays and back.
021     * 
022     * 
023     */
024    public final class HexSupport {
025        
026        private static final String[] HEX_TABLE = new String[]{
027            "00", "01", "02", "03", "04", "05", "06", "07", "08", "09", "0a", "0b", "0c", "0d", "0e", "0f",
028            "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "1a", "1b", "1c", "1d", "1e", "1f",
029            "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "2a", "2b", "2c", "2d", "2e", "2f",
030            "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "3a", "3b", "3c", "3d", "3e", "3f",
031            "40", "41", "42", "43", "44", "45", "46", "47", "48", "49", "4a", "4b", "4c", "4d", "4e", "4f",
032            "50", "51", "52", "53", "54", "55", "56", "57", "58", "59", "5a", "5b", "5c", "5d", "5e", "5f",
033            "60", "61", "62", "63", "64", "65", "66", "67", "68", "69", "6a", "6b", "6c", "6d", "6e", "6f",
034            "70", "71", "72", "73", "74", "75", "76", "77", "78", "79", "7a", "7b", "7c", "7d", "7e", "7f",
035            "80", "81", "82", "83", "84", "85", "86", "87", "88", "89", "8a", "8b", "8c", "8d", "8e", "8f",
036            "90", "91", "92", "93", "94", "95", "96", "97", "98", "99", "9a", "9b", "9c", "9d", "9e", "9f",
037            "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7", "a8", "a9", "aa", "ab", "ac", "ad", "ae", "af",
038            "b0", "b1", "b2", "b3", "b4", "b5", "b6", "b7", "b8", "b9", "ba", "bb", "bc", "bd", "be", "bf",
039            "c0", "c1", "c2", "c3", "c4", "c5", "c6", "c7", "c8", "c9", "ca", "cb", "cc", "cd", "ce", "cf",
040            "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", "d8", "d9", "da", "db", "dc", "dd", "de", "df",
041            "e0", "e1", "e2", "e3", "e4", "e5", "e6", "e7", "e8", "e9", "ea", "eb", "ec", "ed", "ee", "ef",
042            "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "f9", "fa", "fb", "fc", "fd", "fe", "ff",
043        };
044        private static final int[] INT_OFFSETS = new int[]{
045            24,16,8,0
046        };
047        
048        private HexSupport() {
049        }
050        
051        /**
052         * @param hex
053         * @return
054         */
055        public static byte[] toBytesFromHex(String hex) {
056            byte rc[] = new byte[hex.length() / 2];
057            for (int i = 0; i < rc.length; i++) {
058                String h = hex.substring(i * 2, i * 2 + 2);
059                int x = Integer.parseInt(h, 16);
060                rc[i] = (byte) x;
061            }
062            return rc;
063        }
064    
065        /**
066         * @param bytes
067         * @return
068         */
069        public static String toHexFromBytes(byte[] bytes) {
070            StringBuffer rc = new StringBuffer(bytes.length * 2);
071            for (int i = 0; i < bytes.length; i++) {
072                rc.append(HEX_TABLE[0xFF & bytes[i]]);
073            }
074            return rc.toString();
075        }
076    
077        /**
078         * 
079         * @param value 
080         * @param trim if the leading 0's should be trimmed off.
081         * @return
082         */
083        public static String toHexFromInt(int value, boolean trim) {
084            StringBuffer rc = new StringBuffer(INT_OFFSETS.length*2);
085            for (int i = 0; i < INT_OFFSETS.length; i++) {
086                    int b = 0xFF & (value>>INT_OFFSETS[i]);
087                    if( !(trim && b == 0) ) { 
088                            rc.append(HEX_TABLE[b]);
089                            trim=false;
090                    }
091            }
092            return rc.toString();
093        }
094    
095    }