001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq;
018    
019    import javax.jms.MessageConsumer;
020    
021    /**
022     * An extended JMS interface that adds the ability to be notified when a 
023     * message is available for consumption using the receive*() methods
024     * which is useful in Ajax style subscription models.
025     * 
026     * 
027     */
028    public interface MessageAvailableConsumer extends MessageConsumer {
029    
030        /**
031         * Sets the listener used to notify synchronous consumers that there is a message
032         * available so that the {@link MessageConsumer#receiveNoWait()} can be called.
033         */
034        void setAvailableListener(MessageAvailableListener availableListener);
035    
036        /**
037         * Gets the listener used to notify synchronous consumers that there is a message
038         * available so that the {@link MessageConsumer#receiveNoWait()} can be called.
039         */
040        MessageAvailableListener getAvailableListener();
041    }