1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/*
* Copyright 2001-2004 The Apache Software Foundation.
*
* Licensed 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.commons.codec.binary;
import org.apache.commons.codec.BinaryDecoder;
import org.apache.commons.codec.BinaryEncoder;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.EncoderException;
/**
* Hex encoder and decoder.
*
* @since 1.1
* @author Apache Software Foundation
* @version $Id: Hex.java,v 1.13 2004/04/18 18:22:33 ggregory Exp $
*/
public class Hex implements BinaryEncoder, BinaryDecoder {
/**
* Used building output as Hex
*/
private static final char[] DIGITS = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
/**
* Converts an array of characters representing hexidecimal values into an
* array of bytes of those same values. The returned array will be half the
* length of the passed array, as it takes two characters to represent any
* given byte. An exception is thrown if the passed char array has an odd
* number of elements.
*
* @param data An array of characters containing hexidecimal digits
* @return A byte array containing binary data decoded from
* the supplied char array.
* @throws DecoderException Thrown if an odd number or illegal of characters
* is supplied
*/
public static byte[] decodeHex(char[] data) throws DecoderException {
int len = data.length;
if ((len & 0x01) != 0) {
throw new DecoderException("Odd number of characters.");
}
byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++) {
int f = toDigit(data[j], j) << 4;
j++;
f = f | toDigit(data[j], j);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
/**
* Converts a hexadecimal character to an integer.
*
* @param ch A character to convert to an integer digit
* @param index The index of the character in the source
* @return An integer
* @throws DecoderException Thrown if ch is an illegal hex character
*/
protected static int toDigit(char ch, int index) throws DecoderException {
int digit = Character.digit(ch, 16);
if (digit == -1) {
throw new DecoderException("Illegal hexadecimal charcter " + ch + " at index " + index);
}
return digit;
}
/**
* Converts an array of bytes into an array of characters representing the hexidecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @return A char[] containing hexidecimal characters
*/
public static char[] encodeHex(byte[] data) {
int l = data.length;
char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++) {
out[j++] = DIGITS[(0xF0 & data[i]) >>> 4 ];
out[j++] = DIGITS[ 0x0F & data[i] ];
}
return out;
}
/**
* Converts an array of character bytes representing hexidecimal values into an
* array of bytes of those same values. The returned array will be half the
* length of the passed array, as it takes two characters to represent any
* given byte. An exception is thrown if the passed char array has an odd
* number of elements.
*
* @param array An array of character bytes containing hexidecimal digits
* @return A byte array containing binary data decoded from
* the supplied byte array (representing characters).
* @throws DecoderException Thrown if an odd number of characters is supplied
* to this function
* @see #decodeHex(char[])
*/
public byte[] decode(byte[] array) throws DecoderException {
return decodeHex(new String(array).toCharArray());
}
/**
* Converts a String or an array of character bytes representing hexidecimal values into an
* array of bytes of those same values. The returned array will be half the
* length of the passed String or array, as it takes two characters to represent any
* given byte. An exception is thrown if the passed char array has an odd
* number of elements.
*
* @param object A String or, an array of character bytes containing hexidecimal digits
* @return A byte array containing binary data decoded from
* the supplied byte array (representing characters).
* @throws DecoderException Thrown if an odd number of characters is supplied
* to this function or the object is not a String or char[]
* @see #decodeHex(char[])
*/
public Object decode(Object object) throws DecoderException {
try {
char[] charArray = object instanceof String ? ((String) object).toCharArray() : (char[]) object;
return decodeHex(charArray);
} catch (ClassCastException e) {
throw new DecoderException(e.getMessage());
}
}
/**
* Converts an array of bytes into an array of bytes for the characters representing the
* hexidecimal values of each byte in order. The returned array will be
* double the length of the passed array, as it takes two characters to
* represent any given byte.
*
* @param array a byte[] to convert to Hex characters
* @return A byte[] containing the bytes of the hexidecimal characters
* @see #encodeHex(byte[])
*/
public byte[] encode(byte[] array) {
return new String(encodeHex(array)).getBytes();
}
/**
* Converts a String or an array of bytes into an array of characters representing the
* hexidecimal values of each byte in order. The returned array will be
* double the length of the passed String or array, as it takes two characters to
* represent any given byte.
*
* @param object a String, or byte[] to convert to Hex characters
* @return A char[] containing hexidecimal characters
* @throws EncoderException Thrown if the given object is not a String or byte[]
* @see #encodeHex(byte[])
*/
public Object encode(Object object) throws EncoderException {
try {
byte[] byteArray = object instanceof String ? ((String) object).getBytes() : (byte[]) object;
return encodeHex(byteArray);
} catch (ClassCastException e) {
throw new EncoderException(e.getMessage());
}
}
}
|
