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1   /*
2    * $Id$
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  package org.apache.struts.tiles;
22  
23  import jakarta.servlet.ServletException;
24  
25  import org.apache.struts.Globals;
26  import org.apache.struts.action.ActionServlet;
27  import org.apache.struts.action.RequestProcessor;
28  import org.apache.struts.config.ModuleConfig;
29  
30  
31  /**
32   * <p>
33   * WebLogic (at least v6 and v7) attempts to serialize the TilesRequestProcessor
34   * when re-deploying the Webapp in development mode. The TilesRequestProcessor
35   * is not serializable, and loses the Tiles definitions. This results in
36   * NullPointerException and/or NotSerializableException when using the app after
37   * automatic redeploy.
38   * </p>
39   * <p>
40   * This bug report proposes a workaround for this problem, in the hope it will
41   * help others and maybe motivate an actual fix.
42   * </p>
43   * <p>
44   * The attached class extends the Struts Action servlet and fixes the problem by
45   * reloading the Tiles definitions when they have disappeared.
46   * </p>
47   * <p>
48   * For background discussion see
49   * http://issues.apache.org/bugzilla/show_bug.cgi?id=26322
50   * </p>
51   * @version $Rev$ $Date$
52   * @since 1.2.1
53   */
54  public class RedeployableActionServlet extends ActionServlet {
55      private static final long serialVersionUID = -3277829251603784258L;
56  
57      private TilesRequestProcessor tileProcessor;
58  
59      protected synchronized RequestProcessor
60              getRequestProcessor(ModuleConfig config) throws ServletException {
61  
62          if (tileProcessor != null) {
63              TilesRequestProcessor processor = (TilesRequestProcessor) super.getRequestProcessor(config);
64              return processor;
65          }
66  
67          // reset the request processor
68          String requestProcessorKey = Globals.REQUEST_PROCESSOR_KEY +
69                  config.getPrefix();
70          getServletContext().removeAttribute(requestProcessorKey);
71  
72          // create a new request processor instance
73          TilesRequestProcessor processor = (TilesRequestProcessor) super.getRequestProcessor(config);
74  
75          tileProcessor = processor;
76  
77          try {
78              // reload Tiles defs
79              DefinitionsFactory factory = processor.getDefinitionsFactory();
80              factory.init(factory.getConfig(), getServletContext());
81              // System.out.println("reloaded tiles-definitions");
82          } catch (DefinitionsFactoryException e) {
83              e.printStackTrace();
84          }
85  
86          return processor;
87      }
88  }