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