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.transport.discovery;
018    
019    import java.io.IOException;
020    
021    import javax.jms.JMSException;
022    
023    import org.apache.activemq.Service;
024    import org.apache.activemq.command.DiscoveryEvent;
025    
026    /**
027     * An agent used to discover other instances of a service. 
028     * 
029     * We typically use a discovery agent to auto-discover JMS clients and JMS brokers on a network
030     *
031     * 
032     */
033    public interface DiscoveryAgent extends Service {
034    
035        /**
036         * Sets the discovery listener
037         * @param listener
038         */
039        void setDiscoveryListener(DiscoveryListener listener);
040    
041        /**
042         * register a service
043         * @param name
044         * @param details
045         * @throws JMSException
046         */
047        void registerService(String name) throws IOException;
048        
049        /**
050         * A process actively using a service may see it go down before the DiscoveryAgent notices the
051         * service's failure.  That process can use this method to notify the DiscoveryAgent of the failure
052         * so that other listeners of this DiscoveryAgent can also be made aware of the failure.
053         */
054        void serviceFailed(DiscoveryEvent event) throws IOException;
055        
056    }