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.event;
021    
022    import java.util.EventObject;
023    
024    /**
025     * This event is used to signal the availability of the specified key. This is
026     * usually used for inter-branch synchronization using the
027     * {@link org.apache.commons.pipeline.stage.RaiseKeyAvailableEventStage RaiseKeyAvailableEventStage}
028     * and/or the {@link org.apache.commons.pipeline.stage.KeyWaitBufferStage KeyWaitBufferStage}.
029     */
030    public class KeyAvailableEvent<T> extends EventObject {
031        /**
032             * 
033             */
034            private static final long serialVersionUID = -7704631412431162164L;
035        private T key;
036        
037        /** Creates a new instance of KeyAvailableEvent */
038        public KeyAvailableEvent(Object source, T key) {
039            super(source);
040            this.key = key;
041        }
042        
043        /**
044         * Returns the key.
045         */
046        public T getKey() {
047            return this.key;
048        }
049    }