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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.jar;
20  
21  import java.io.IOException;
22  import java.io.OutputStream;
23  
24  import org.apache.commons.compress.archivers.zip.JarMarker;
25  import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
26  import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;
27  
28  /**
29   * Subclass that adds a special extra field to the very first entry which allows the created archive to be used as an executable jar on Solaris.
30   *
31   * @NotThreadSafe
32   */
33  public class JarArchiveOutputStream extends ZipArchiveOutputStream {
34  
35      private boolean jarMarkerAdded;
36  
37      public JarArchiveOutputStream(final OutputStream out) {
38          super(out);
39      }
40  
41      /**
42       * Constructs a new instance that wraps the output stream using the provided encoding.
43       *
44       * @param out      the output stream to wrap
45       * @param encoding the encoding to use. Use null for the platform default.
46       * @since 1.10
47       */
48      public JarArchiveOutputStream(final OutputStream out, final String encoding) {
49          super(out);
50          setEncoding(encoding);
51      }
52  
53      // @throws ClassCastException if entry is not an instance of ZipArchiveEntry
54      @Override
55      public void putArchiveEntry(final ZipArchiveEntry entry) throws IOException {
56          if (!jarMarkerAdded) {
57              entry.addAsFirstExtraField(JarMarker.getInstance());
58              jarMarkerAdded = true;
59          }
60          super.putArchiveEntry(entry);
61      }
62  }