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1   package org.apache.velocity.runtime.resource.loader;
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.InputStream;
23  
24  import java.util.Hashtable;
25  import java.util.Vector;
26  import java.util.Map;
27  import java.util.HashMap;
28  
29  import org.apache.velocity.util.StringUtils;
30  import org.apache.velocity.runtime.resource.Resource;
31  import org.apache.velocity.exception.ResourceNotFoundException;
32  import org.apache.commons.collections.ExtendedProperties;
33  
34  /**
35   * <p>
36   * ResourceLoader to load templates from multiple Jar files.
37   * </p>
38   * <p>
39   * The configuration of the JarResourceLoader is straightforward -
40   * You simply add the JarResourceLoader to the configuration via
41   * </p>
42   * <p><pre>
43   *    resource.loader = jar
44   *    jar.resource.loader.class = org.apache.velocity.runtime.resource.loader.JarResourceLoader
45   *    jar.resource.loader.path = list of JAR &lt;URL&gt;s
46   * </pre></p>
47   *
48   * <p> So for example, if you had a jar file on your local filesystem, you could simply do
49   *    <pre>
50   *    jar.resource.loader.path = jar:file:/opt/myfiles/jar1.jar
51   *    </pre>
52   * </p>
53   * <p> Note that jar specification for the <code>.path</code> configuration property
54   * conforms to the same rules for the java.net.JarUrlConnection class.
55   * </p>
56   *
57   * <p> For a working example, see the unit test case,
58   *  org.apache.velocity.test.MultiLoaderTestCase class
59   * </p>
60   *
61   * @author <a href="mailto:mailmur@yahoo.com">Aki Nieminen</a>
62   * @author <a href="mailto:daveb@miceda-data.com">Dave Bryson</a>
63   * @version $Id: JarResourceLoader.java 471259 2006-11-04 20:26:57Z henning $
64   */
65  public class JarResourceLoader extends ResourceLoader
66  {
67      /**
68       * Maps entries to the parent JAR File
69       * Key = the entry *excluding* plain directories
70       * Value = the JAR URL
71       */
72      private Map entryDirectory = new HashMap(559);
73  
74      /**
75       * Maps JAR URLs to the actual JAR
76       * Key = the JAR URL
77       * Value = the JAR
78       */
79      private Map jarfiles = new HashMap(89);
80  
81      /**
82       * Called by Velocity to initialize the loader
83       * @param configuration
84       */
85      public void init( ExtendedProperties configuration)
86      {
87          log.trace("JarResourceLoader : initialization starting.");
88  
89          // rest of Velocity engine still use legacy Vector
90          // and Hashtable classes. Classes are implicitly
91          // synchronized even if we don't need it.
92          Vector paths = configuration.getVector("path");
93          StringUtils.trimStrings(paths);
94  
95          /*
96           *  support the old version but deprecate with a log message
97           */
98  
99          if( paths == null || paths.size() == 0)
100         {
101             paths = configuration.getVector("resource.path");
102             StringUtils.trimStrings(paths);
103 
104             if (paths != null && paths.size() > 0)
105             {
106                 log.info("JarResourceLoader : you are using a deprecated configuration"
107                          + " property for the JarResourceLoader -> '<name>.resource.loader.resource.path'."
108                          + " Please change to the conventional '<name>.resource.loader.path'.");
109             }
110         }
111 
112         if (paths != null)
113         {
114             log.debug("JarResourceLoader # of paths : " + paths.size() );
115 
116             for ( int i=0; i<paths.size(); i++ )
117             {
118                 loadJar( (String)paths.get(i) );
119             }
120         }
121 
122         log.trace("JarResourceLoader : initialization complete.");
123     }
124 
125     private void loadJar( String path )
126     {
127         if (log.isDebugEnabled())
128         {
129             log.debug("JarResourceLoader : trying to load \"" + path + "\"");
130         }
131 
132         // Check path information
133         if ( path == null )
134         {
135             log.error("JarResourceLoader : can not load JAR - JAR path is null");
136         }
137         if ( !path.startsWith("jar:") )
138         {
139             log.error("JarResourceLoader : JAR path must start with jar: -> " +
140                 "see java.net.JarURLConnection for information");
141         }
142         if ( !path.endsWith("!/") )
143         {
144             path += "!/";
145         }
146 
147         // Close the jar if it's already open
148         // this is useful for a reload
149         closeJar( path );
150 
151         // Create a new JarHolder
152         JarHolder temp = new JarHolder( rsvc,  path );
153         // Add it's entries to the entryCollection
154         addEntries( temp.getEntries() );
155         // Add it to the Jar table
156         jarfiles.put( temp.getUrlPath(), temp );
157     }
158 
159     /**
160      * Closes a Jar file and set its URLConnection
161      * to null.
162      */
163     private void closeJar( String path )
164     {
165         if ( jarfiles.containsKey(path) )
166         {
167             JarHolder theJar = (JarHolder)jarfiles.get(path);
168             theJar.close();
169         }
170     }
171 
172     /**
173      * Copy all the entries into the entryDirectory
174      * It will overwrite any duplicate keys.
175      */
176     private void addEntries( Hashtable entries )
177     {
178         entryDirectory.putAll( entries );
179     }
180 
181     /**
182      * Get an InputStream so that the Runtime can build a
183      * template with it.
184      *
185      * @param source name of template to get
186      * @return InputStream containing the template
187      * @throws ResourceNotFoundException if template not found
188      *         in the file template path.
189      */
190     public InputStream getResourceStream( String source )
191         throws ResourceNotFoundException
192     {
193         InputStream results = null;
194 
195         if (org.apache.commons.lang.StringUtils.isEmpty(source))
196         {
197             throw new ResourceNotFoundException("Need to have a resource!");
198         }
199 
200         String normalizedPath = StringUtils.normalizePath( source );
201 
202         if ( normalizedPath == null || normalizedPath.length() == 0 )
203         {
204             String msg = "JAR resource error : argument " + normalizedPath +
205                 " contains .. and may be trying to access " +
206                 "content outside of template root.  Rejected.";
207 
208             log.error( "JarResourceLoader : " + msg );
209 
210             throw new ResourceNotFoundException ( msg );
211         }
212 
213         /*
214          *  if a / leads off, then just nip that :)
215          */
216         if ( normalizedPath.startsWith("/") )
217         {
218             normalizedPath = normalizedPath.substring(1);
219         }
220 
221         if ( entryDirectory.containsKey( normalizedPath ) )
222         {
223             String jarurl  = (String)entryDirectory.get( normalizedPath );
224 
225             if ( jarfiles.containsKey( jarurl ) )
226             {
227                 JarHolder holder = (JarHolder)jarfiles.get( jarurl );
228                 results =  holder.getResource( normalizedPath );
229                 return results;
230             }
231         }
232 
233         throw new ResourceNotFoundException( "JarResourceLoader Error: cannot find resource " +
234           source );
235 
236     }
237 
238 
239     // TODO: SHOULD BE DELEGATED TO THE JARHOLDER
240 
241     /**
242      * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#isSourceModified(org.apache.velocity.runtime.resource.Resource)
243      */
244     public boolean isSourceModified(Resource resource)
245     {
246         return true;
247     }
248 
249     /**
250      * @see org.apache.velocity.runtime.resource.loader.ResourceLoader#getLastModified(org.apache.velocity.runtime.resource.Resource)
251      */
252     public long getLastModified(Resource resource)
253     {
254         return 0;
255     }
256 }