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