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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;
18  
19  import org.apache.commons.vfs2.FileObject;
20  import org.apache.commons.vfs2.FileSystemException;
21  import org.apache.commons.vfs2.FileSystemOptions;
22  
23  /**
24   * Description.
25   */
26  public abstract class CompositeFileProvider extends AbstractFileProvider {
27  
28      private static final int INITIAL_BUFSZ = 80;
29  
30      public CompositeFileProvider() {
31          super();
32      }
33  
34      /**
35       * The schemes known.
36       *
37       * @return Array of supported schemes.
38       */
39      protected abstract String[] getSchemes();
40  
41      /**
42       * Locates a file object, by absolute URI.
43       *
44       * @param baseFile The base FileObject.
45       * @param uri The file to find.
46       * @param fileSystemOptions The options for the FileSystem.
47       * @return A FileObject for the located file.
48       * @throws FileSystemException if an error occurs.
49       */
50      @Override
51      public FileObjectect.html#FileObject">FileObject findFile(final FileObject baseFile, final String uri, final FileSystemOptions fileSystemOptions)
52              throws FileSystemException {
53          final StringBuilder buf = new StringBuilder(INITIAL_BUFSZ);
54  
55          UriParser.extractScheme(getContext().getFileSystemManager().getSchemes(), uri, buf);
56  
57          final String[] schemes = getSchemes();
58          for (final String scheme : schemes) {
59              buf.insert(0, ":");
60              buf.insert(0, scheme);
61          }
62  
63          final FileObject fo = getContext().getFileSystemManager().resolveFile(buf.toString(), fileSystemOptions);
64          return fo;
65      }
66  }