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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.myfaces.trinidad.resource;
20  
21  import java.io.File;
22  import java.io.IOException;
23  
24  import java.net.URL;
25  
26  import org.apache.myfaces.trinidad.logging.TrinidadLogger;
27  
28  /**
29   * A resource loader implementation which loads resources
30   * from a directory.  The returned resource URL will be null
31   * for file resources that do not exist, or for relative paths
32   * that attempt to access paths outside the root directory.
33   *
34   */
35  public class DirectoryResourceLoader extends ResourceLoader
36  {
37    /**
38     * Constructs a new DirectoryResourceLoader.
39     *
40     * @param directory  the root directory
41     */
42    public DirectoryResourceLoader(
43      File directory)
44    {
45      if (directory == null)
46        throw new NullPointerException();
47  
48      if (!directory.isDirectory())
49        throw new IllegalArgumentException();
50  
51      _directory = directory;
52      
53      try
54      {
55        _directoryPath = _directory.getCanonicalPath();
56      }
57      catch (IOException ex)
58      {
59        throw new IllegalArgumentException(ex);
60      }    
61    }
62  
63    /**
64     * Constructs a new DirectoryResourceLoader.
65     *
66     * @param directory  the root directory
67     * @param parent     the parent resource loader
68     */
69    public DirectoryResourceLoader(
70      File           directory,
71      ResourceLoader parent)
72    {
73      super(parent);
74  
75      if (directory == null)
76        throw new NullPointerException();
77  
78      if (!directory.isDirectory())
79        throw new IllegalArgumentException();
80  
81      _directory = directory;
82      
83      try
84      {
85        _directoryPath = _directory.getCanonicalPath();
86      }
87      catch (IOException ex)
88      {
89        throw new IllegalArgumentException(ex);
90      }
91  
92    }
93  
94    @Override
95    protected URL findResource(
96      String path) throws IOException
97    {
98      if (path.charAt(0) == '/')
99        path = path.substring(1);
100 
101     // construct the relative file under the "root" directory
102     File file = new File(_directory, path).getCanonicalFile();
103     
104 
105     // file path should contain the "root" directory path, not be outside it
106     boolean isContained = file.getCanonicalPath().startsWith(_directoryPath);
107     
108     // return null if relative paths were used, 
109     // or if the file does not exist,
110     // otherwise return an URL to the file resource
111     // 2006-08-01: -= Simon Lessard =-
112     //             File.toURL is deprecated in JDK 6.0 because the method 
113     //             does not escape invalid characters, toURI().toURL is the 
114     //             preferred way as of JDK 6.0.
115     return (isContained && file.exists()) ? file.toURI().toURL() : null;
116   }
117 
118   private final File _directory;
119   private final String _directoryPath;
120   private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(
121     DirectoryResourceLoader.class);
122 }