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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
    25  /**
    26   * The purpose of this class is to allow one to load and execute Page
    27   * modules.
    28   *
    29   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    30   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    31   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    32   * @version $Id: PageLoader.java 1773378 2016-12-09 13:19:59Z tv $
    33   */
    34  public class PageLoader
    35      extends GenericLoader<Page>
    36      implements Loader<Page>
    37  {
    38      /** The single instance of this class. */
    39      private static PageLoader instance = new PageLoader();
    40
    41      /**
    42       * These ctor's are private to force clients to use getInstance()
    43       * to access this class.
    44       */
    45      private PageLoader()
    46      {
    47          super();
    48      }
    49
    50      /**
    51       * Attempts to load and execute the external page.
    52       *
    53       * @param pipelineData Turbine information.
    54       * @param name Name of object that will execute the page.
    55       * @throws Exception a generic exception.
    56       */
    57      @Override
    58      public void exec(PipelineData pipelineData, String name)
    59              throws Exception
    60      {
    61          // Execute page
    62          getAssembler(name).build(pipelineData);
    63      }
    64
    65      /**
    66       * Pulls out an instance of the object by name.  Name is just the
    67       * single name of the object.
    68       *
    69       * @param name Name of object instance.
    70       * @return A Screen with the specified name, or null.
    71       * @throws Exception a generic exception.
    72       */
    73      @Override
    74      public Page getAssembler(String name)
    75          throws Exception
    76      {
    77          return getAssembler(Page.class, name);
    78      }
    79
    80      /**
    81       * @see org.apache.turbine.modules.Loader#getCacheSize()
    82       */
    83      @Override
    84      public int getCacheSize()
    85      {
    86          return PageLoader.getConfiguredCacheSize();
    87      }
    88
    89      /**
    90       * The method through which this class is accessed.
    91       *
    92       * @return The single instance of this class.
    93       */
    94      public static PageLoader getInstance()
    95      {
    96          return instance;
    97      }
    98
    99      /**
    100      * Helper method to get the configured cache size for this module
    101      *
    102      * @return the configure cache size
    103      */
    104     private static int getConfiguredCacheSize()
    105     {
    106         return Turbine.getConfiguration().getInt(Page.CACHE_SIZE_KEY,
    107                 Page.CACHE_SIZE_DEFAULT);
    108     }
    109 }