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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    *                                                              *
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11   *                                                              *
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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.                                           *
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19  
20  package org.apache.james.services;
21  
22  import java.io.File;
23  import java.io.FileNotFoundException;
24  import java.io.InputStream;
25  import java.io.IOException;
26  
27  /**
28   * This service is used by components that wants to lookup a File resource
29   * from the application folder.
30   * 
31   * @since James 2.4
32   */
33  public interface FileSystem {
34  
35      String ROLE = "org.apache.james.services.FileSystem";
36  
37      /**
38       * to retrieve a resource. this is typically a file resource,
39       * but depending on the implementation, this could also be from classpath or
40       * from another source. 
41       * 
42       * @param url the url of the resource
43       * @return the resource as an input stream
44       * @throws IOException if the resource could not be accessed
45       */
46      public InputStream getResource(String url) throws IOException;
47  
48      /**
49       * Used to retrieve a specific file in the application context 
50       * 
51       * @param fileURL file
52       * @return the File found
53       * @throws FileNotFoundException if the file cannot be found/read
54       */
55      public File getFile(String fileURL) throws FileNotFoundException;
56  
57      /**
58       * Return the base folder used by the application 
59       */
60      public File getBasedir() throws FileNotFoundException;
61  
62  }