001package org.apache.turbine.pipeline;
002
003import java.util.HashMap;
004import java.util.Map;
005
006
007/*
008 * Licensed to the Apache Software Foundation (ASF) under one
009 * or more contributor license agreements.  See the NOTICE file
010 * distributed with this work for additional information
011 * regarding copyright ownership.  The ASF licenses this file
012 * to you under the Apache License, Version 2.0 (the
013 * "License"); you may not use this file except in compliance
014 * with the License.  You may obtain a copy of the License at
015 *
016 *   http://www.apache.org/licenses/LICENSE-2.0
017 *
018 * Unless required by applicable law or agreed to in writing,
019 * software distributed under the License is distributed on an
020 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
021 * KIND, either express or implied.  See the License for the
022 * specific language governing permissions and limitations
023 * under the License.
024 */
025
026
027/**
028 * <p>A <b>PipelineData</b> is a holder for data being passed from one
029 * Valve to the next.
030 * The detailed contract for a Valve is included in the description of
031 * the <code>invoke()</code> method below.</p>
032 *
033 * <b>HISTORICAL NOTE</b>:  The "PipelineData" name was assigned to this
034 * holder as it functions similarly to the RunData object, but without
035 * the additional methods
036 *
037 * @author <a href="mailto:epugh@opensourceconnections.com">Eric Pugh</a>
038 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
039 */
040public class DefaultPipelineData implements PipelineData
041{
042    private final Map<Class<?>, Map<Class<?>, ? super Object>> map =
043        new HashMap<Class<?>, Map<Class<?>, ? super Object>>();
044
045    /**
046     * Put a configured map of objects into the pipeline data object
047     *
048     * @param key the key class
049     * @param value the value map
050     */
051    @Override
052    public void put(Class<?> key, Map<Class<?>, ? super Object> value)
053    {
054        map.put(key, value);
055    }
056
057    /**
058     * Get the configured map of objects for the given key
059     *
060     * @param key the key class
061     * @return the value map or null if no such key exists
062     */
063    @Override
064    public Map<Class<?>, ? super Object> get(Class<?> key)
065    {
066        return map.get(key);
067    }
068
069    /**
070     * Get a value from the configured map of objects for the given keys
071     *
072     * @param key the key class
073     * @param innerKey the key into the value map
074     * @return the inner value or null if no such keys exist
075     */
076    @Override
077    @SuppressWarnings("unchecked")
078    public <T> T get(Class<?> key, Class<T> innerKey)
079    {
080        Map<Class<?>, ? super Object> innerMap = get(key);
081        if (innerMap == null)
082        {
083            return null;
084        }
085        return (T) innerMap.get(innerKey);
086    }
087}