/**
* 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 java.io.IOException;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.command.ActiveMQTextMessage;
import org.apache.activemq.util.FactoryFinder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*
*/
public class CommandMessageListener implements MessageListener {
private static final Logger LOG = LoggerFactory.getLogger(CommandMessageListener.class);
private Session session;
private MessageProducer producer;
private CommandHandler handler;
public CommandMessageListener(Session session) {
this.session = session;
}
public void onMessage(Message message) {
if (LOG.isDebugEnabled()) {
LOG.debug("Received command: " + message);
}
if (message instanceof TextMessage) {
TextMessage request = (TextMessage)message;
try {
Destination replyTo = message.getJMSReplyTo();
if (replyTo == null) {
LOG.warn("Ignored message as no JMSReplyTo set: " + message);
return;
}
Message response = processCommand(request);
addReplyHeaders(request, response);
getProducer().send(replyTo, response);
} catch (Exception e) {
LOG.error("Failed to process message due to: " + e + ". Message: " + message, e);
}
} else {
LOG.warn("Ignoring invalid message: " + message);
}
}
protected void addReplyHeaders(TextMessage request, Message response) throws JMSException {
String correlationID = request.getJMSCorrelationID();
if (correlationID != null) {
response.setJMSCorrelationID(correlationID);
}
}
/**
* Processes an incoming JMS message returning the response message
*/
public Message processCommand(TextMessage request) throws Exception {
TextMessage response = session.createTextMessage();
getHandler().processCommand(request, response);
return response;
}
/**
* Processes an incoming command from a console and returning the text to
* output
*/
public String processCommandText(String line) throws Exception {
TextMessage request = new ActiveMQTextMessage();
request.setText(line);
TextMessage response = new ActiveMQTextMessage();
getHandler().processCommand(request, response);
return response.getText();
}
public Session getSession() {
return session;
}
public MessageProducer getProducer() throws JMSException {
if (producer == null) {
producer = getSession().createProducer(null);
}
return producer;
}
public CommandHandler getHandler() throws IllegalAccessException, IOException, InstantiationException, ClassNotFoundException {
if (handler == null) {
handler = createHandler();
}
return handler;
}
private CommandHandler createHandler() throws IllegalAccessException, IOException, ClassNotFoundException, InstantiationException {
FactoryFinder factoryFinder = new FactoryFinder("META-INF/services/org/apache/activemq/broker/");
return (CommandHandler)factoryFinder.newInstance("agent");
}
}