001: /*
002: * The Apache Software License, Version 1.1
003: *
004: *
005: * Copyright (c) 1999 The Apache Software Foundation. All rights
006: * reserved.
007: *
008: * Redistribution and use in source and binary forms, with or without
009: * modification, are permitted provided that the following conditions
010: * are met:
011: *
012: * 1. Redistributions of source code must retain the above copyright
013: * notice, this list of conditions and the following disclaimer.
014: *
015: * 2. Redistributions in binary form must reproduce the above copyright
016: * notice, this list of conditions and the following disclaimer in
017: * the documentation and/or other materials provided with the
018: * distribution.
019: *
020: * 3. The end-user documentation included with the redistribution,
021: * if any, must include the following acknowledgment:
022: * "This product includes software developed by the
023: * Apache Software Foundation (http://www.apache.org/)."
024: * Alternately, this acknowledgment may appear in the software itself,
025: * if and wherever such third-party acknowledgments normally appear.
026: *
027: * 4. The names "Xerces" and "Apache Software Foundation" must
028: * not be used to endorse or promote products derived from this
029: * software without prior written permission. For written
030: * permission, please contact apache@apache.org.
031: *
032: * 5. Products derived from this software may not be called "Apache",
033: * nor may "Apache" appear in their name, without prior written
034: * permission of the Apache Software Foundation.
035: *
036: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
037: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
038: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
039: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
040: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
041: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
042: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
043: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
044: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
045: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
046: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
047: * SUCH DAMAGE.
048: * ====================================================================
049: *
050: * This software consists of voluntary contributions made by many
051: * individuals on behalf of the Apache Software Foundation and was
052: * originally based on software copyright (c) 1999, International
053: * Business Machines, Inc., http://www.apache.org. For more
054: * information on the Apache Software Foundation, please see
055: * <http://www.apache.org/>.
056: */
057:
058: package org.apache.xerces.utils;
059:
060: import java.lang.*;
061:
062: /**
063: * format validation
064: *
065: * This class encodes/decodes hexadecimal data
066: * @author Jeffrey Rodriguez
067: * @version $Id: HexBin.java,v 1.7 2001/05/29 22:19:02 neilg Exp $
068: */
069:
070: public final class HexBin {
071: static private final int BASELENGTH = 255;
072: static private final int LOOKUPLENGTH = 16;
073: static private byte[] hexNumberTable = new byte[BASELENGTH];
074: static private byte[] lookUpHexAlphabet = new byte[LOOKUPLENGTH];
075:
076: static {
077: for (int i = 0; i < BASELENGTH; i++) {
078: hexNumberTable[i] = -1;
079: }
080: for (int i = '9'; i >= '0'; i--) {
081: hexNumberTable[i] = (byte) (i - '0');
082: }
083: for (int i = 'F'; i >= 'A'; i--) {
084: hexNumberTable[i] = (byte) (i - 'A' + 10);
085: }
086: for (int i = 'f'; i >= 'a'; i--) {
087: hexNumberTable[i] = (byte) (i - 'a' + 10);
088: }
089:
090: for (int i = 0; i < 10; i++)
091: lookUpHexAlphabet[i] = (byte) ('0' + i);
092: for (int i = 10; i <= 15; i++)
093: lookUpHexAlphabet[i] = (byte) ('A' + i - 10);
094: }
095:
096: /**
097: * byte to be tested if it is Base64 alphabet
098: *
099: * @param octect
100: * @return
101: */
102: static boolean isHex(byte octect) {
103: //shall we ignore white space? JEFF??
104: return (hexNumberTable[octect] != -1);
105: }
106:
107: /**
108: * Array of bytes to check against Hex Table
109: *
110: * @param arrayOctect
111: * @return
112: */
113: static boolean isArrayByteHex(byte[] arrayOctect) {
114: if (arrayOctect == null)
115: return false;
116: int length = arrayOctect.length;
117: if (length % 2 != 0)
118: return false;
119: for (int i = 0; i < length; i++) {
120: if (HexBin.isHex(arrayOctect[i]) == false)
121: return false;
122: }
123: return true;
124: }
125:
126: public static boolean isHex(String isValidString) {
127: if (isValidString == null)
128: return false;
129: return (isArrayByteHex(isValidString.getBytes()));
130: }
131:
132: /**
133: * array of byte to encode
134: *
135: * @param binaryData
136: * @return return encode binary array
137: */
138: static public byte[] encode(byte[] binaryData) {
139: if (binaryData == null)
140: return null;
141: int lengthData = binaryData.length;
142: int lengthEncode = lengthData * 2;
143: byte[] encodedData = new byte[lengthEncode];
144: for (int i = 0; i < lengthData; i++) {
145: encodedData[i * 2] = lookUpHexAlphabet[binaryData[i] >> 4];
146: encodedData[i * 2 + 1] = lookUpHexAlphabet[binaryData[i] & 0xf];
147: }
148: return encodedData;
149: }
150:
151: static public byte[] decode(byte[] binaryData) {
152: if (binaryData == null)
153: return null;
154: int lengthData = binaryData.length;
155: if (lengthData % 2 != 0)
156: return null;
157:
158: int lengthDecode = lengthData / 2;
159: byte[] decodedData = new byte[lengthDecode];
160: for (int i = 0; i < lengthDecode; i++) {
161: decodedData[i] = (byte) ((hexNumberTable[binaryData[i * 2]] << 4) | hexNumberTable[binaryData[i * 2 + 1]]);
162: }
163: return decodedData;
164: }
165:
166: static public int getDecodedDataLength(byte[] hexData) {
167: if (!isArrayByteHex(hexData))
168: return -1;
169:
170: return hexData.length / 2;
171: }
172: }
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