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.kahadb.util;
018
019 /**
020 * Used to convert to hex from byte arrays and back.
021 *
022 * @version $Revision: 712224 $
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 }