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
|
/*
* 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.tools.zip;
import static org.apache.tools.zip.ZipConstants.BYTE_MASK;
/**
* Utility class that represents a two byte integer with conversion
* rules for the big endian byte order of ZIP files.
*
*/
public final class ZipShort implements Cloneable {
private static final int BYTE_1_MASK = 0xFF00;
private static final int BYTE_1_SHIFT = 8;
private final int value;
/**
* Create instance from a number.
* @param value the int to store as a ZipShort
* @since 1.1
*/
public ZipShort (int value) {
this.value = value;
}
/**
* Create instance from bytes.
* @param bytes the bytes to store as a ZipShort
* @since 1.1
*/
public ZipShort (byte[] bytes) {
this(bytes, 0);
}
/**
* Create instance from the two bytes starting at offset.
* @param bytes the bytes to store as a ZipShort
* @param offset the offset to start
* @since 1.1
*/
public ZipShort (byte[] bytes, int offset) {
value = ZipShort.getValue(bytes, offset);
}
/**
* Get value as two bytes in big endian byte order.
* @return the value as a a two byte array in big endian byte order
* @since 1.1
*/
public byte[] getBytes() {
byte[] result = new byte[2];
putShort(value, result, 0);
return result;
}
/**
* put the value as two bytes in big endian byte order.
* @param value the Java int to convert to bytes
* @param buf the output buffer
* @param offset
* The offset within the output buffer of the first byte to be written.
* must be non-negative and no larger than <tt>buf.length-2</tt>
*/
public static void putShort(int value, byte[] buf, int offset) {
buf[offset] = (byte) (value & BYTE_MASK);
buf[offset+1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
}
/**
* Get value as Java int.
* @return value as a Java int
* @since 1.1
*/
public int getValue() {
return value;
}
/**
* Get value as two bytes in big endian byte order.
* @param value the Java int to convert to bytes
* @return the converted int as a byte array in big endian byte order
*/
public static byte[] getBytes(int value) {
byte[] result = new byte[2];
result[0] = (byte) (value & BYTE_MASK);
result[1] = (byte) ((value & BYTE_1_MASK) >> BYTE_1_SHIFT);
return result;
}
/**
* Helper method to get the value as a java int from two bytes starting at given array offset
* @param bytes the array of bytes
* @param offset the offset to start
* @return the corresponding java int value
*/
public static int getValue(byte[] bytes, int offset) {
int value = (bytes[offset + 1] << BYTE_1_SHIFT) & BYTE_1_MASK;
value += (bytes[offset] & BYTE_MASK);
return value;
}
/**
* Helper method to get the value as a java int from a two-byte array
* @param bytes the array of bytes
* @return the corresponding java int value
*/
public static int getValue(byte[] bytes) {
return getValue(bytes, 0);
}
/**
* Override to make two instances with same value equal.
* @param o an object to compare
* @return true if the objects are equal
* @since 1.1
*/
@Override
public boolean equals(Object o) {
if (o == null || !(o instanceof ZipShort)) {
return false;
}
return value == ((ZipShort) o).getValue();
}
/**
* Override to make two instances with same value equal.
* @return the value stored in the ZipShort
* @since 1.1
*/
@Override
public int hashCode() {
return value;
}
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException cnfe) {
// impossible
throw new RuntimeException(cnfe);
}
}
@Override
public String toString() {
return "ZipShort value: " + value;
}
}
|
