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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   * http://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.Arrays;
22  
23  /**
24   * Wrapper for extra field data that doesn't conform to the recommended format of header-tag + size + data.
25   *
26   * <p>
27   * The header-id is artificial (and not listed as a known ID in <a href="https://www.pkware.com/documents/casestudies/APPNOTE.TXT">APPNOTE.TXT</a>). Since it
28   * isn't used anywhere except to satisfy the ZipExtraField contract it shouldn't matter anyway.
29   * </p>
30   *
31   * @since 1.1
32   * @NotThreadSafe
33   */
34  public final class UnparseableExtraFieldData implements ZipExtraField {
35      private static final ZipShort HEADER_ID = new ZipShort(0xACC1);
36  
37      private byte[] localFileData;
38      private byte[] centralDirectoryData;
39  
40      /**
41       * The actual data to put into central directory.
42       *
43       * @return The CentralDirectoryData value
44       */
45      @Override
46      public byte[] getCentralDirectoryData() {
47          return centralDirectoryData == null ? getLocalFileDataData() : ZipUtil.copy(centralDirectoryData);
48      }
49  
50      /**
51       * Length of the complete extra field in the central directory.
52       *
53       * @return The CentralDirectoryLength value
54       */
55      @Override
56      public ZipShort getCentralDirectoryLength() {
57          return centralDirectoryData == null ? getLocalFileDataLength() : new ZipShort(centralDirectoryData.length);
58      }
59  
60      /**
61       * The Header-ID.
62       *
63       * @return a completely arbitrary value that should be ignored.
64       */
65      @Override
66      public ZipShort getHeaderId() {
67          return HEADER_ID;
68      }
69  
70      /**
71       * The actual data to put into local file data.
72       *
73       * @return The LocalFileDataData value
74       */
75      @Override
76      public byte[] getLocalFileDataData() {
77          return ZipUtil.copy(localFileData);
78      }
79  
80      /**
81       * Length of the complete extra field in the local file data.
82       *
83       * @return The LocalFileDataLength value
84       */
85      @Override
86      public ZipShort getLocalFileDataLength() {
87          return new ZipShort(localFileData == null ? 0 : localFileData.length);
88      }
89  
90      /**
91       * Populate data from this array as if it was in central directory data.
92       *
93       * @param buffer the buffer to read data from
94       * @param offset offset into buffer to read data
95       * @param length the length of data
96       */
97      @Override
98      public void parseFromCentralDirectoryData(final byte[] buffer, final int offset, final int length) {
99          centralDirectoryData = Arrays.copyOfRange(buffer, offset, offset + length);
100         if (localFileData == null) {
101             parseFromLocalFileData(buffer, offset, length);
102         }
103     }
104 
105     /**
106      * Populate data from this array as if it was in local file data.
107      *
108      * @param buffer the buffer to read data from
109      * @param offset offset into buffer to read data
110      * @param length the length of data
111      */
112     @Override
113     public void parseFromLocalFileData(final byte[] buffer, final int offset, final int length) {
114         localFileData = Arrays.copyOfRange(buffer, offset, offset + length);
115     }
116 
117 }