/**
* 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.broker.util;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.ExceptionListener;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.Service;
import org.apache.activemq.advisory.AdvisorySupport;
import org.apache.activemq.util.ServiceStopper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
/**
* An agent which listens to commands on a JMS destination
*
* @version $Revision: 695445 $
* @org.apache.xbean.XBean
*/
public class CommandAgent implements Service, InitializingBean, DisposableBean, FactoryBean, ExceptionListener {
private static final Log LOG = LogFactory.getLog(CommandAgent.class);
private String brokerUrl = "vm://localhost";
private String username;
private String password;
private ConnectionFactory connectionFactory;
private Connection connection;
private Destination commandDestination;
private CommandMessageListener listener;
private Session session;
private MessageConsumer consumer;
public void start() throws Exception {
session = getConnection().createSession(false, Session.AUTO_ACKNOWLEDGE);
listener = new CommandMessageListener(session);
Destination destination = getCommandDestination();
if (LOG.isDebugEnabled()) {
LOG.debug("Agent subscribing to control destination: " + destination);
}
consumer = session.createConsumer(destination);
consumer.setMessageListener(listener);
}
public void stop() throws Exception {
ServiceStopper stopper = new ServiceStopper();
if (consumer != null) {
try {
consumer.close();
consumer = null;
} catch (JMSException e) {
stopper.onException(this, e);
}
}
if (session != null) {
try {
session.close();
session = null;
} catch (JMSException e) {
stopper.onException(this, e);
}
}
if (connection != null) {
try {
connection.close();
connection = null;
} catch (JMSException e) {
stopper.onException(this, e);
}
}
stopper.throwFirstException();
}
// the following methods ensure that we are created on startup and the
// lifecycles respected
// TODO there must be a simpler way?
public void afterPropertiesSet() throws Exception {
start();
}
public void destroy() throws Exception {
stop();
}
public Object getObject() throws Exception {
return this;
}
public Class getObjectType() {
return getClass();
}
public boolean isSingleton() {
return true;
}
// Properties
// -------------------------------------------------------------------------
public String getBrokerUrl() {
return brokerUrl;
}
public void setBrokerUrl(String brokerUrl) {
this.brokerUrl = brokerUrl;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public ConnectionFactory getConnectionFactory() {
if (connectionFactory == null) {
connectionFactory = new ActiveMQConnectionFactory(brokerUrl);
}
return connectionFactory;
}
public void setConnectionFactory(ConnectionFactory connectionFactory) {
this.connectionFactory = connectionFactory;
}
public Connection getConnection() throws JMSException {
if (connection == null) {
connection = createConnection();
connection.setExceptionListener(this);
connection.start();
}
return connection;
}
public void setConnection(Connection connection) {
this.connection = connection;
}
public Destination getCommandDestination() {
if (commandDestination == null) {
commandDestination = createCommandDestination();
}
return commandDestination;
}
public void setCommandDestination(Destination commandDestination) {
this.commandDestination = commandDestination;
}
protected Connection createConnection() throws JMSException {
return getConnectionFactory().createConnection(username, password);
}
protected Destination createCommandDestination() {
return AdvisorySupport.getAgentDestination();
}
public void onException(JMSException exception) {
try {
stop();
} catch (Exception e) {
}
}
}