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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.vfs2.provider.jar;
18  
19  import java.util.ArrayList;
20  import java.util.Arrays;
21  import java.util.Collection;
22  import java.util.Collections;
23  
24  import org.apache.commons.vfs2.Capability;
25  import org.apache.commons.vfs2.FileName;
26  import org.apache.commons.vfs2.FileObject;
27  import org.apache.commons.vfs2.FileSystem;
28  import org.apache.commons.vfs2.FileSystemException;
29  import org.apache.commons.vfs2.FileSystemOptions;
30  import org.apache.commons.vfs2.FileType;
31  import org.apache.commons.vfs2.provider.AbstractFileName;
32  import org.apache.commons.vfs2.provider.LayeredFileName;
33  import org.apache.commons.vfs2.provider.zip.ZipFileProvider;
34  
35  /**
36   * A file system provider for Jar files. Provides read-only file systems. This provides access to Jar specific features
37   * like Signing and Manifest Attributes.
38   */
39  public class JarFileProvider extends ZipFileProvider {
40  
41      static final Collection<Capability> capabilities;
42  
43      static {
44          final Collection<Capability> combined = new ArrayList<>();
45          combined.addAll(ZipFileProvider.capabilities);
46          combined.addAll(Arrays.asList(new Capability[] { Capability.ATTRIBUTES, Capability.FS_ATTRIBUTES,
47                  Capability.SIGNING, Capability.MANIFEST_ATTRIBUTES, Capability.VIRTUAL }));
48          capabilities = Collections.unmodifiableCollection(combined);
49      }
50  
51      public JarFileProvider() {
52          super();
53      }
54  
55      /**
56       * Creates a layered file system. This method is called if the file system is not cached.
57       *
58       * @param scheme The URI scheme.
59       * @param file The file to create the file system on top of.
60       * @return The file system.
61       */
62      @Override
63      protected FileSystem doCreateFileSystem(final String scheme, final FileObject file,
64              final FileSystemOptions fileSystemOptions) throws FileSystemException {
65          final AbstractFileName name = new LayeredFileName(scheme, file.getName(), FileName.ROOT_PATH, FileType.FOLDER);
66          return new JarFileSystem(name, file, fileSystemOptions);
67      }
68  
69      @Override
70      public Collection<Capability> getCapabilities() {
71          return capabilities;
72      }
73  }