001package org.apache.turbine.modules;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import org.apache.turbine.Turbine;
023import org.apache.turbine.pipeline.PipelineData;
024
025/**
026 * The purpose of this class is to allow one to load and execute
027 * Action modules.
028 *
029 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
030 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
031 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
032 * @version $Id: ActionLoader.java 1695634 2015-08-13 00:35:47Z tv $
033 */
034public class ActionLoader
035    extends GenericLoader<Action>
036    implements Loader<Action>
037{
038    /** The single instance of this class. */
039    private static ActionLoader instance = new ActionLoader();
040
041    /**
042     * These ctor's are private to force clients to use getInstance()
043     * to access this class.
044     */
045    private ActionLoader()
046    {
047        super();
048    }
049
050    /**
051     * Attempts to load and execute the external action.
052     *
053     * @param pipelineData Turbine information.
054     * @param name Name of object that will execute the action.
055     * @exception Exception a generic exception.
056     */
057    @Override
058    public void exec(PipelineData pipelineData, String name)
059                throws Exception
060    {
061        getAssembler(name).perform(pipelineData);
062    }
063
064    /**
065     * Pulls out an instance of the object by name.  Name is just the
066     * single name of the object.
067     *
068     * @param name Name of object instance.
069     * @return An Action with the specified name, or null.
070     * @exception Exception a generic exception.
071     */
072    @Override
073    public Action getAssembler(String name)
074        throws Exception
075    {
076        return getAssembler(Action.class, name);
077    }
078
079    /**
080     * @see org.apache.turbine.modules.Loader#getCacheSize()
081     */
082    @Override
083    public int getCacheSize()
084    {
085        return ActionLoader.getConfiguredCacheSize();
086    }
087
088    /**
089     * The method through which this class is accessed.
090     *
091     * @return The single instance of this class.
092     */
093    public static ActionLoader getInstance()
094    {
095        return instance;
096    }
097
098    /**
099     * 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(Action.CACHE_SIZE_KEY,
106                Action.CACHE_SIZE_DEFAULT);
107    }
108}