1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.compress.archivers.zip;
18
19 import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD;
20
21 import java.io.Serializable;
22
23 import org.apache.commons.compress.utils.ByteUtils;
24
25 /**
26 * Utility class that represents a four byte integer with conversion rules for the little-endian byte order of ZIP files.
27 *
28 * @Immutable
29 */
30 public final class ZipLong implements Cloneable, Serializable {
31 private static final long serialVersionUID = 1L;
32
33 /** Central File Header Signature */
34 public static final ZipLong CFH_SIG = new ZipLong(0X02014B50L);
35
36 /** Local File Header Signature */
37 public static final ZipLong LFH_SIG = new ZipLong(0X04034B50L);
38
39 /**
40 * Data Descriptor signature.
41 *
42 * <p>
43 * Actually, PKWARE uses this as marker for split/spanned archives and other archivers have started to use it as Data Descriptor signature (as well).
44 * </p>
45 *
46 * @since 1.1
47 */
48 public static final ZipLong DD_SIG = new ZipLong(0X08074B50L);
49
50 /**
51 * Value stored in size and similar fields if ZIP64 extensions are used.
52 *
53 * @since 1.3
54 */
55 static final ZipLong ZIP64_MAGIC = new ZipLong(ZipConstants.ZIP64_MAGIC);
56
57 /**
58 * Marks ZIP archives that were supposed to be split or spanned but only needed a single segment in then end (so are actually neither split nor spanned).
59 *
60 * <p>
61 * This is the "PK00" prefix found in some archives.
62 * </p>
63 *
64 * @since 1.5
65 */
66 public static final ZipLong SINGLE_SEGMENT_SPLIT_MARKER = new ZipLong(0X30304B50L);
67
68 /**
69 * Archive extra data record signature.
70 *
71 * @since 1.5
72 */
73 public static final ZipLong AED_SIG = new ZipLong(0X08064B50L);
74
75 /**
76 * Gets value as four bytes in big-endian byte order.
77 *
78 * @param value the value to convert
79 * @return value as four bytes in big-endian byte order
80 */
81 public static byte[] getBytes(final long value) {
82 final byte[] result = new byte[WORD];
83 putLong(value, result, 0);
84 return result;
85 }
86
87 /**
88 * Helper method to get the value as a Java long from a four-byte array
89 *
90 * @param bytes the array of bytes
91 * @return the corresponding Java long value
92 */
93 public static long getValue(final byte[] bytes) {
94 return getValue(bytes, 0);
95 }
96
97 /**
98 * Helper method to get the value as a Java long from four bytes starting at given array offset
99 *
100 * @param bytes the array of bytes
101 * @param offset the offset to start
102 * @return the corresponding Java long value
103 */
104 public static long getValue(final byte[] bytes, final int offset) {
105 return ByteUtils.fromLittleEndian(bytes, offset, 4);
106 }
107
108 /**
109 * put the value as four bytes in big-endian byte order.
110 *
111 * @param value the Java long to convert to bytes
112 * @param buf the output buffer
113 * @param offset The offset within the output buffer of the first byte to be written. must be non-negative and no larger than {@code buf.length-4}
114 */
115
116 public static void putLong(final long value, final byte[] buf, final int offset) {
117 ByteUtils.toLittleEndian(buf, value, offset, 4);
118 }
119
120 private final long value;
121
122 /**
123 * Constructs a new instance from bytes.
124 *
125 * @param bytes the bytes to store as a ZipLong
126 */
127 public ZipLong(final byte[] bytes) {
128 this(bytes, 0);
129 }
130
131 /**
132 * Creates instance from the four bytes starting at offset.
133 *
134 * @param bytes the bytes to store as a ZipLong
135 * @param offset the offset to start
136 */
137 public ZipLong(final byte[] bytes, final int offset) {
138 value = ZipLong.getValue(bytes, offset);
139 }
140
141 /**
142 * create instance from a Java int.
143 *
144 * @param value the int to store as a ZipLong
145 * @since 1.15
146 */
147 public ZipLong(final int value) {
148 this.value = value;
149 }
150
151 /**
152 * Creates instance from a number.
153 *
154 * @param value the long to store as a ZipLong
155 */
156 public ZipLong(final long value) {
157 this.value = value;
158 }
159
160 @Override
161 public Object clone() {
162 try {
163 return super.clone();
164 } catch (final CloneNotSupportedException cnfe) {
165 // impossible
166 throw new UnsupportedOperationException(cnfe); // NOSONAR
167 }
168 }
169
170 /**
171 * Override to make two instances with same value equal.
172 *
173 * @param o an object to compare
174 * @return true if the objects are equal
175 */
176 @Override
177 public boolean equals(final Object o) {
178 if (!(o instanceof ZipLong)) {
179 return false;
180 }
181 return value == ((ZipLong) o).getValue();
182 }
183
184 /**
185 * Gets value as four bytes in big-endian byte order.
186 *
187 * @return value as four bytes in big-endian order
188 */
189 public byte[] getBytes() {
190 return ZipLong.getBytes(value);
191 }
192
193 /**
194 * Gets value as a (signed) Java int
195 *
196 * @return value as int
197 * @since 1.15
198 */
199 public int getIntValue() {
200 return (int) value;
201 }
202
203 /**
204 * Gets value as Java long.
205 *
206 * @return value as a long
207 */
208 public long getValue() {
209 return value;
210 }
211
212 /**
213 * Override to make two instances with same value equal.
214 *
215 * @return the value stored in the ZipLong
216 */
217 @Override
218 public int hashCode() {
219 return (int) value;
220 }
221
222 public void putLong(final byte[] buf, final int offset) {
223 putLong(value, buf, offset);
224 }
225
226 @Override
227 public String toString() {
228 return "ZipLong value: " + value;
229 }
230 }
231