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.util;
018    
019    import java.io.Serializable;
020    import java.util.ArrayList;
021    import java.util.Iterator;
022    import java.util.List;
023    import javax.jms.Connection;
024    import javax.jms.Destination;
025    import javax.jms.JMSException;
026    import javax.jms.Message;
027    import javax.jms.MessageProducer;
028    import javax.jms.Session;
029    import javax.naming.NamingException;
030    
031    import org.apache.log4j.AppenderSkeleton;
032    import org.apache.log4j.spi.LoggingEvent;
033    
034    /**
035     * An abstract base class for implementation inheritence for a log4j JMS
036     * appender
037     * 
038     * 
039     */
040    public abstract class JmsLogAppenderSupport extends AppenderSkeleton {
041    
042        public static final int JMS_PUBLISH_ERROR_CODE = 61616;
043    
044        private Connection connection;
045        private Session session;
046        private MessageProducer producer;
047        private boolean allowTextMessages = true;
048        private String subjectPrefix = "log4j.";
049    
050        public JmsLogAppenderSupport() {
051        }
052    
053        public Connection getConnection() throws JMSException, NamingException {
054            if (connection == null) {
055                connection = createConnection();
056            }
057            return connection;
058        }
059    
060        public void setConnection(Connection connection) {
061            this.connection = connection;
062        }
063    
064        public Session getSession() throws JMSException, NamingException {
065            if (session == null) {
066                session = createSession();
067            }
068            return session;
069        }
070    
071        public void setSession(Session session) {
072            this.session = session;
073        }
074    
075        public MessageProducer getProducer() throws JMSException, NamingException {
076            if (producer == null) {
077                producer = createProducer();
078            }
079            return producer;
080        }
081    
082        public void setProducer(MessageProducer producer) {
083            this.producer = producer;
084        }
085    
086        public void close() {
087            List<JMSException> errors = new ArrayList<JMSException>();
088            if (producer != null) {
089                try {
090                    producer.close();
091                } catch (JMSException e) {
092                    errors.add(e);
093                }
094            }
095            if (session != null) {
096                try {
097                    session.close();
098                } catch (JMSException e) {
099                    errors.add(e);
100                }
101            }
102            if (connection != null) {
103                try {
104                    connection.close();
105                } catch (JMSException e) {
106                    errors.add(e);
107                }
108            }
109            for (Iterator<JMSException> iter = errors.iterator(); iter.hasNext();) {
110                JMSException e = iter.next();
111                getErrorHandler().error("Error closing JMS resources: " + e, e, JMS_PUBLISH_ERROR_CODE);
112            }
113        }
114    
115        public boolean requiresLayout() {
116            return false;
117        }
118    
119        public void activateOptions() {
120            try {
121                // lets ensure we're all created
122                getProducer();
123            } catch (Exception e) {
124                getErrorHandler().error("Could not create JMS resources: " + e, e, JMS_PUBLISH_ERROR_CODE);
125            }
126        }
127    
128        // Implementation methods
129        // -------------------------------------------------------------------------
130        protected abstract Connection createConnection() throws JMSException, NamingException;
131    
132        protected Session createSession() throws JMSException, NamingException {
133            return getConnection().createSession(false, Session.AUTO_ACKNOWLEDGE);
134        }
135    
136        protected MessageProducer createProducer() throws JMSException, NamingException {
137            return getSession().createProducer(null);
138        }
139    
140        private static final ThreadLocal<Object> APPENDING = new ThreadLocal<Object>();
141    
142        protected void append(LoggingEvent event) {
143            if( APPENDING.get()==null ) {
144                APPENDING.set(true);
145                try {
146                    Message message = createMessage(event);
147                    Destination destination = getDestination(event);
148                    getProducer().send(destination, message);
149                } catch (Exception e) {
150                    getErrorHandler().error("Could not send message due to: " + e, e, JMS_PUBLISH_ERROR_CODE, event);
151                } finally {
152                    APPENDING.remove();
153                }
154            }
155        }
156    
157        protected Message createMessage(LoggingEvent event) throws JMSException, NamingException {
158            Message answer = null;
159            Object value = event.getMessage();
160            if (allowTextMessages && value instanceof String) {
161                answer = getSession().createTextMessage((String)value);
162            } else {
163                answer = getSession().createObjectMessage((Serializable)value);
164            }
165            answer.setStringProperty("level", event.getLevel().toString());
166            answer.setIntProperty("levelInt", event.getLevel().toInt());
167            answer.setStringProperty("threadName", event.getThreadName());
168            return answer;
169        }
170    
171        protected Destination getDestination(LoggingEvent event) throws JMSException, NamingException {
172            String name = subjectPrefix + event.getLoggerName();
173            return getSession().createTopic(name);
174        }
175    }