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