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1   package org.apache.turbine.pipeline;
2   
3   
4   /*
5    * Licensed to the Apache Software Foundation (ASF) under one
6    * or more contributor license agreements.  See the NOTICE file
7    * distributed with this work for additional information
8    * regarding copyright ownership.  The ASF licenses this file
9    * to you under the Apache License, Version 2.0 (the
10   * "License"); you may not use this file except in compliance
11   * with the License.  You may obtain a copy of the License at
12   *
13   *   http://www.apache.org/licenses/LICENSE-2.0
14   *
15   * Unless required by applicable law or agreed to in writing,
16   * software distributed under the License is distributed on an
17   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18   * KIND, either express or implied.  See the License for the
19   * specific language governing permissions and limitations
20   * under the License.
21   */
22  
23  
24  import java.io.IOException;
25  
26  import org.apache.commons.configuration.Configuration;
27  import org.apache.turbine.TurbineConstants;
28  import org.apache.turbine.annotation.TurbineConfiguration;
29  import org.apache.turbine.annotation.TurbineLoader;
30  import org.apache.turbine.annotation.TurbineService;
31  import org.apache.turbine.modules.Page;
32  import org.apache.turbine.modules.PageLoader;
33  import org.apache.turbine.services.template.TemplateService;
34  import org.apache.turbine.util.TurbineException;
35  
36  /**
37   * Implements the Page Generation portion of the "Turbine classic"
38   * processing pipeline (from the Turbine 2.x series).
39   *
40   * @author <a href="mailto:epugh@opensourceConnections.com">Eric Pugh</a>
41   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
42   * @version $Id: ExecutePageValve.java 1709648 2015-10-20 17:08:10Z tv $
43   */
44  public class ExecutePageValve
45      extends AbstractValve
46  {
47      /** Injected service instance */
48      @TurbineService
49      private TemplateService templateService;
50  
51      /** Injected loader instance */
52      @TurbineLoader( Page.class )
53      private PageLoader pageLoader;
54  
55      /** Injected configuration instance */
56      @TurbineConfiguration
57      private Configuration config;
58  
59      /**
60       * @see org.apache.turbine.pipeline.Valve#invoke(PipelineData, ValveContext)
61       */
62      @Override
63      public void invoke(PipelineData pipelineData, ValveContext context)
64          throws IOException, TurbineException
65      {
66          try
67          {
68              executePage(pipelineData);
69          }
70          catch (Exception e)
71          {
72              throw new TurbineException(e);
73          }
74  
75          // Pass control to the next Valve in the Pipeline
76          context.invokeNext(pipelineData);
77      }
78  
79      /**
80       * execute the page generation.
81       *
82       * @param pipelineData The run-time data.
83       */
84      protected void executePage(PipelineData pipelineData)
85          throws Exception
86      {
87          // Start the execution phase. DefaultPage will execute the
88          // appropriate action as well as get the Layout from the
89          // Screen and then execute that. The Layout is then
90          // responsible for executing the Navigation and Screen
91          // modules.
92          //
93          // Note that by default, this cannot be overridden from
94          // parameters passed in via post/query data. This is for
95          // security purposes.  You should really never need more
96          // than just the default page.  If you do, add logic to
97          // DefaultPage to do what you want.
98  
99          String defaultPage = (templateService == null)
100         ? null : templateService.getDefaultPageName(pipelineData);
101 
102         if (defaultPage == null)
103         {
104             /*
105              * In this case none of the template services are running.
106              * The application may be using ECS for views, or a
107              * decendent of RawScreen is trying to produce output.
108              * If there is a 'page.default' property in the TR.props
109              * then use that, otherwise return DefaultPage which will
110              * handle ECS view scenarios and RawScreen scenarios. The
111              * app developer can still specify the 'page.default'
112              * if they wish but the DefaultPage should work in
113              * most cases.
114              */
115             defaultPage = config.getString(TurbineConstants.PAGE_DEFAULT_KEY,
116                     TurbineConstants.PAGE_DEFAULT_DEFAULT);
117         }
118 
119         pageLoader.exec(pipelineData, defaultPage);
120     }
121 }