001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     * 
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     * 
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.    
018     */ 
019    
020    package org.apache.commons.pipeline;
021    
022    /**
023     * <p>This interface represents a factory that is used by a {@link Pipeline} to create
024     * a driver for a {@link Stage} when that stage is added to the pipeline. The factory
025     * pattern is used here to ensure that each stage is run by a unique driver
026     * instance.</p>
027     *
028     * <p>In order to guarantee that StageDriverFactory instances can be used
029     * effectively in configuration frameworks, each StageDriverFactory implementation
030     * <em>must</em> provide a no-argument constructor.</p>
031     */
032    public interface StageDriverFactory<T extends StageDriver> {
033        /**
034         * This method is used to create a driver that will run the specified stage
035         * in the specified context.
036         * @param stage The stage to be run by the newly created driver.
037         * @param context The context in which the stage will be run
038         * @return The newly created driver
039         */
040        public T createStageDriver(Stage stage, StageContext context);
041    }