001    /*
002     * Copyright 2009 Red Hat, Inc.
003     * Red Hat licenses this file to you under the Apache License, version
004     * 2.0 (the "License"); you may not use this file except in compliance
005     * with the License.  You may obtain a copy of the License at
006     *    http://www.apache.org/licenses/LICENSE-2.0
007     * Unless required by applicable law or agreed to in writing, software
008     * distributed under the License is distributed on an "AS IS" BASIS,
009     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
010     * implied.  See the License for the specific language governing
011     * permissions and limitations under the License.
012     */
013    
014    package org.hornetq.api.core.client;
015    
016    /**
017     * 
018     * A MessageHandler is used to receive message <em>asynchronously</em>.
019     * 
020     * To receive messages asynchronously, a MessageHandler is set on a ClientConsumer.
021     * Every time the consumer will receive a message, it will call the handler's {@code onMessage()} method.
022     * 
023     * @author <a href="mailto:tim.fox@jboss.com">Tim Fox</a>
024     *
025     * @see ClientConsumer#setMessageHandler(MessageHandler)
026     */
027    public interface MessageHandler
028    {
029       /**
030        * Notifies the MessageHandler that a message has been received.
031        * 
032        * @param message a message
033        */
034       void onMessage(ClientMessage message);
035    }