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1   package org.apache.turbine.modules;
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.turbine.Turbine;
23  import org.apache.turbine.pipeline.PipelineData;
24  import org.apache.turbine.util.RunData;
25  
26  /**
27   * The purpose of this class is to allow one to load and execute Page
28   * modules.
29   *
30   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
31   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
32   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
33   * @version $Id: PageLoader.java 1078552 2011-03-06 19:58:46Z tv $
34   */
35  public class PageLoader
36      extends GenericLoader<Page>
37      implements Loader<Page>
38  {
39      /** The single instance of this class. */
40      private static PageLoader instance = new PageLoader();
41  
42      /**
43       * These ctor's are private to force clients to use getInstance()
44       * to access this class.
45       */
46      private PageLoader()
47      {
48          super();
49      }
50  
51      /**
52       * Attempts to load and execute the external page.
53       * @deprecated Use PipelineData version instead.
54       * @param data Turbine information.
55       * @param name Name of object that will execute the page.
56       * @exception Exception a generic exception.
57       */
58      @Deprecated
59      @Override
60      public void exec(RunData data, String name)
61              throws Exception
62      {
63          // Execute page
64          getAssembler(name).build(data);
65      }
66  
67      /**
68       * Attempts to load and execute the external page.
69       *
70       * @param data Turbine information.
71       * @param name Name of object that will execute the page.
72       * @exception Exception a generic exception.
73       */
74      @Override
75      public void exec(PipelineData pipelineData, String name)
76              throws Exception
77      {
78          // Execute page
79          getAssembler(name).build(pipelineData);
80      }
81  
82  
83  
84      /**
85       * Pulls out an instance of the object by name.  Name is just the
86       * single name of the object. This is equal to getInstance but
87       * returns an Assembler object and is needed to fulfil the Loader
88       * interface.
89       *
90       * @param name Name of object instance.
91       * @return A Screen with the specified name, or null.
92       * @exception Exception a generic exception.
93       */
94      public Page getAssembler(String name)
95          throws Exception
96      {
97          return getAssembler(Page.NAME, name);
98      }
99  
100     /**
101      * @see org.apache.turbine.modules.Loader#getCacheSize()
102      */
103     public int getCacheSize()
104     {
105         return PageLoader.getConfiguredCacheSize();
106     }
107 
108     /**
109      * The method through which this class is accessed.
110      *
111      * @return The single instance of this class.
112      */
113     public static PageLoader getInstance()
114     {
115         return instance;
116     }
117 
118     /**
119      * Helper method to get the configured cache size for this module
120      *
121      * @return the configure cache size
122      */
123     private static int getConfiguredCacheSize()
124     {
125         return Turbine.getConfiguration().getInt(Page.CACHE_SIZE_KEY,
126                 Page.CACHE_SIZE_DEFAULT);
127     }
128 }