1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.commons.compress.archivers.zip;
20
21 import java.util.zip.ZipException;
22
23 import org.apache.commons.compress.utils.ByteUtils;
24
25 /**
26 * If this extra field is added as the very first extra field of the archive, Solaris will consider it an executable jar file.
27 *
28 * @Immutable
29 */
30 public final class JarMarker implements ZipExtraField {
31
32 static final ZipShort ID = new ZipShort(0xCAFE);
33 private static final ZipShort NULL = new ZipShort(0);
34 private static final JarMarker DEFAULT = new JarMarker();
35
36 /**
37 * Since JarMarker is stateless we can always use the same instance.
38 *
39 * @return the DEFAULT jarmaker.
40 */
41 public static JarMarker getInstance() {
42 return DEFAULT;
43 }
44
45 /** No-arg constructor */
46 public JarMarker() {
47 // empty
48 }
49
50 /**
51 * The actual data to put central directory - without Header-ID or length specifier.
52 *
53 * @return the data
54 */
55 @Override
56 public byte[] getCentralDirectoryData() {
57 return ByteUtils.EMPTY_BYTE_ARRAY;
58 }
59
60 /**
61 * Length of the extra field in the central directory - without Header-ID or length specifier.
62 *
63 * @return 0
64 */
65 @Override
66 public ZipShort getCentralDirectoryLength() {
67 return NULL;
68 }
69
70 /**
71 * The Header-ID.
72 *
73 * @return the header id
74 */
75 @Override
76 public ZipShort getHeaderId() {
77 return ID;
78 }
79
80 /**
81 * The actual data to put into local file data - without Header-ID or length specifier.
82 *
83 * @return the data
84 */
85 @Override
86 public byte[] getLocalFileDataData() {
87 return ByteUtils.EMPTY_BYTE_ARRAY;
88 }
89
90 /**
91 * Length of the extra field in the local file data - without Header-ID or length specifier.
92 *
93 * @return 0
94 */
95 @Override
96 public ZipShort getLocalFileDataLength() {
97 return NULL;
98 }
99
100 /**
101 * Doesn't do anything special since this class always uses the same data in central directory and local file data.
102 */
103 @Override
104 public void parseFromCentralDirectoryData(final byte[] buffer, final int offset, final int length) throws ZipException {
105 parseFromLocalFileData(buffer, offset, length);
106 }
107
108 /**
109 * Populate data from this array as if it was in local file data.
110 *
111 * @param data an array of bytes
112 * @param offset the start offset
113 * @param length the number of bytes in the array from offset
114 * @throws ZipException on error
115 */
116 @Override
117 public void parseFromLocalFileData(final byte[] data, final int offset, final int length) throws ZipException {
118 if (length != 0) {
119 throw new ZipException("JarMarker doesn't expect any data");
120 }
121 }
122 }