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.logging.log4j.core.net;
018    
019    import org.apache.logging.log4j.LogManager;
020    import org.apache.logging.log4j.Logger;
021    import org.apache.logging.log4j.core.AbstractServer;
022    import org.apache.logging.log4j.core.LogEvent;
023    
024    import javax.jms.JMSException;
025    import javax.jms.ObjectMessage;
026    import javax.naming.Context;
027    import javax.naming.NameNotFoundException;
028    import javax.naming.NamingException;
029    
030    /**
031     * Abstract base class for receiving LogEvents over JMS. This class expects all messages to be serialized log events.
032     */
033    public abstract class AbstractJMSReceiver extends AbstractServer implements javax.jms.MessageListener {
034    
035        /**
036         * Logger to capture diagnostics.
037         */
038        protected Logger logger = LogManager.getLogger(this.getClass().getName());
039    
040        /**
041         * Listener that receives the event.
042         * @param message The received message.
043         */
044        public void onMessage(javax.jms.Message message) {
045    
046            try {
047                if (message instanceof ObjectMessage) {
048                    ObjectMessage objectMessage = (ObjectMessage) message;
049                    log((LogEvent) objectMessage.getObject());
050                } else {
051                    logger.warn("Received message is of type " + message.getJMSType()
052                        + ", was expecting ObjectMessage.");
053                }
054            } catch (JMSException jmse) {
055                logger.error("Exception thrown while processing incoming message.",
056                    jmse);
057            }
058        }
059    
060        /**
061         * Looks up an object from the Context.
062         * @param ctx The Context.
063         * @param name The name of the object to locate.
064         * @return The object.
065         * @throws NamingException if an error occurs.
066         */
067        protected Object lookup(Context ctx, String name) throws NamingException {
068            try {
069                return ctx.lookup(name);
070            } catch (NameNotFoundException e) {
071                logger.error("Could not find name [" + name + "].");
072                throw e;
073            }
074        }
075    
076    }