ActiveMQ example source code file (JmsLogAppenderSupport.java)

This example ActiveMQ source code file (JmsLogAppenderSupport.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

connection, connection, destination, io, jms_publish_error_code, jms_publish_error_code, jmsexception, jmsexception, jmslogappendersupport, message, messageproducer, naming, namingexception, namingexception, session, string, util

The ActiveMQ JmsLogAppenderSupport.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.activemq.util;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.naming.NamingException;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.spi.LoggingEvent;

/**
 * An abstract base class for implementation inheritence for a log4j JMS
 * appender
 * 
 * 
 */
public abstract class JmsLogAppenderSupport extends AppenderSkeleton {

    public static final int JMS_PUBLISH_ERROR_CODE = 61616;

    private Connection connection;
    private Session session;
    private MessageProducer producer;
    private boolean allowTextMessages = true;
    private String subjectPrefix = "log4j.";

    public JmsLogAppenderSupport() {
    }

    public Connection getConnection() throws JMSException, NamingException {
        if (connection == null) {
            connection = createConnection();
        }
        return connection;
    }

    public void setConnection(Connection connection) {
        this.connection = connection;
    }

    public Session getSession() throws JMSException, NamingException {
        if (session == null) {
            session = createSession();
        }
        return session;
    }

    public void setSession(Session session) {
        this.session = session;
    }

    public MessageProducer getProducer() throws JMSException, NamingException {
        if (producer == null) {
            producer = createProducer();
        }
        return producer;
    }

    public void setProducer(MessageProducer producer) {
        this.producer = producer;
    }

    public void close() {
        List<JMSException> errors = new ArrayList();
        if (producer != null) {
            try {
                producer.close();
            } catch (JMSException e) {
                errors.add(e);
            }
        }
        if (session != null) {
            try {
                session.close();
            } catch (JMSException e) {
                errors.add(e);
            }
        }
        if (connection != null) {
            try {
                connection.close();
            } catch (JMSException e) {
                errors.add(e);
            }
        }
        for (Iterator<JMSException> iter = errors.iterator(); iter.hasNext();) {
            JMSException e = iter.next();
            getErrorHandler().error("Error closing JMS resources: " + e, e, JMS_PUBLISH_ERROR_CODE);
        }
    }

    public boolean requiresLayout() {
        return false;
    }

    public void activateOptions() {
        try {
            // lets ensure we're all created
            getProducer();
        } catch (Exception e) {
            getErrorHandler().error("Could not create JMS resources: " + e, e, JMS_PUBLISH_ERROR_CODE);
        }
    }

    // Implementation methods
    // -------------------------------------------------------------------------
    protected abstract Connection createConnection() throws JMSException, NamingException;

    protected Session createSession() throws JMSException, NamingException {
        return getConnection().createSession(false, Session.AUTO_ACKNOWLEDGE);
    }

    protected MessageProducer createProducer() throws JMSException, NamingException {
        return getSession().createProducer(null);
    }

    protected void append(LoggingEvent event) {
        try {
            Message message = createMessage(event);
            Destination destination = getDestination(event);
            getProducer().send(destination, message);
        } catch (Exception e) {
            getErrorHandler().error("Could not send message due to: " + e, e, JMS_PUBLISH_ERROR_CODE, event);
        }
    }

    protected Message createMessage(LoggingEvent event) throws JMSException, NamingException {
        Message answer = null;
        Object value = event.getMessage();
        if (allowTextMessages && value instanceof String) {
            answer = getSession().createTextMessage((String)value);
        } else {
            answer = getSession().createObjectMessage((Serializable)value);
        }
        answer.setStringProperty("level", event.getLevel().toString());
        answer.setIntProperty("levelInt", event.getLevel().toInt());
        answer.setStringProperty("threadName", event.getThreadName());
        return answer;
    }

    protected Destination getDestination(LoggingEvent event) throws JMSException, NamingException {
        String name = subjectPrefix + event.getLoggerName();
        return getSession().createTopic(name);
    }
}