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1   package org.apache.turbine.modules.screens;
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 org.apache.commons.lang3.StringUtils;
23  import org.apache.turbine.annotation.TurbineService;
24  import org.apache.turbine.pipeline.PipelineData;
25  import org.apache.turbine.services.jsp.JspService;
26  import org.apache.turbine.services.template.TemplateService;
27  import org.apache.turbine.util.RunData;
28  
29  /**
30   * Base JSP Screen that should be subclassed by screens that want to
31   * use JSP.  Subclasses should override the doBuildTemplate() method.
32   *
33   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
34   * @author Frank Y. Kim
35   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
36   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
37   * @version $Id$
38   */
39  public class BaseJspScreen
40          extends TemplateScreen
41  {
42      /** The prefix for lookup up screen pages */
43      private static final String prefix = PREFIX + "/";
44  
45      /** Injected service instance */
46      @TurbineService
47      private JspService jspService;
48  
49      /** Injected service instance */
50      @TurbineService
51      private TemplateService templateService;
52  
53      /**
54       * Method that sets up beans and forward the request to the JSP.
55       *
56       * @param pipelineData Turbine information.
57       * @return null - the JSP sends the information.
58       * @throws Exception a generic exception.
59       */
60      @Override
61      public String buildTemplate(PipelineData pipelineData)
62              throws Exception
63      {
64          RunData data = pipelineData.getRunData();
65          String screenTemplate = data.getTemplateInfo().getScreenTemplate();
66          // get the name of the template we want to use
67          String templateName
68              = templateService.getScreenTemplateName(screenTemplate);
69  
70          // The Template Service could not find the Screen
71          if (StringUtils.isEmpty(templateName))
72          {
73              log.error("Screen " + screenTemplate + " not found!");
74              throw new Exception("Could not find screen for " + screenTemplate);
75          }
76  
77          // let service know whether we are using a layout
78          jspService.handleRequest(pipelineData, prefix + templateName,
79                                   getLayout(pipelineData) == null);
80  
81          return null;
82      }
83  
84      /**
85       * Method to be overridden by subclasses to include data in beans, etc.
86       *
87       * @param pipelineData the PipelineData object
88       * @throws Exception a generic exception.
89       */
90      @Override
91      protected void doBuildTemplate(PipelineData pipelineData)
92          throws Exception
93      {
94          // abstract method
95      }
96  }