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1   package org.apache.maven.plugins.shade.resource;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.io.IOException;
23  import java.io.InputStream;
24  import java.util.Iterator;
25  import java.util.List;
26  import java.util.Map;
27  import java.util.jar.Attributes;
28  import java.util.jar.JarEntry;
29  import java.util.jar.JarFile;
30  import java.util.jar.JarOutputStream;
31  import java.util.jar.Manifest;
32  
33  import org.codehaus.plexus.util.IOUtil;
34  
35  /**
36   * A resource processor that allows the arbitrary addition of attributes to
37   * the first MANIFEST.MF that is found in the set of JARs being processed, or
38   * to a newly created manifest for the shaded JAR.
39   *
40   * @author Jason van Zyl
41   * @since 1.2
42   */
43  public class ManifestResourceTransformer
44      implements ResourceTransformer
45  {
46  
47      // Configuration
48      private String mainClass;
49      private Map manifestEntries;
50  
51      // Fields
52      private boolean manifestDiscovered;
53      private Manifest manifest;
54  
55      public boolean canTransformResource( String resource )
56      {
57          if ( JarFile.MANIFEST_NAME.equalsIgnoreCase( resource ) )
58          {
59              return true;
60          }
61  
62          return false;
63      }
64  
65      public void processResource( String resource, InputStream is, List relocators )
66          throws IOException
67      {
68          // We just want to take the first manifest we come across as that's our project's manifest. This is the behavior
69          // now which is situational at best. Right now there is no context passed in with the processing so we cannot
70          // tell what artifact is being processed.
71          if ( !manifestDiscovered )
72          {
73              manifest = new Manifest( is );
74              manifestDiscovered = true;
75              IOUtil.close( is );
76          }
77      }
78  
79      public boolean hasTransformedResource()
80      {
81          return true;
82      }
83  
84      public void modifyOutputStream( JarOutputStream jos )
85          throws IOException
86      {
87          // If we didn't find a manifest, then let's create one.
88          if ( manifest == null )
89          {
90              manifest = new Manifest();
91          }
92  
93          Attributes attributes = manifest.getMainAttributes();
94  
95          if ( mainClass != null )
96          {
97              attributes.put( Attributes.Name.MAIN_CLASS, mainClass );
98          }
99  
100         if ( manifestEntries != null )
101         {
102             for ( Iterator i = manifestEntries.keySet().iterator(); i.hasNext(); )
103             {
104                 String key = (String) i.next();
105                 attributes.put( new Attributes.Name( key ), manifestEntries.get( key ) );
106             }
107         }
108 
109         jos.putNextEntry( new JarEntry( JarFile.MANIFEST_NAME ) );
110         manifest.write( jos );
111     }
112 }