I have been fiddling with JMS Virtual topics. I want to get the example going, But it is having some issues.
I have taken the examples that comes along with ActiveMQ and modified it with Virtual Topics.
TopicPublisher:
/**
* 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.
*/
import java.util.Arrays;
import javax.jms.BytesMessage;
import javax.jms.Connection;
import javax.jms.DeliveryMode;
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 javax.jms.Topic;
import org.apache.activemq.ActiveMQConnectionFactory;
/**
* Use in conjunction with TopicListener to test the performance of ActiveMQ
* Topics.
*/
public class TopicPublisher implements MessageListener {
private static final char[] DATA = "abcdefghijklmnopqrstuvwxyz".toCharArray();
private final Object mutex = new Object();
private Connection connection;
private Session session;
private MessageProducer publisher;
private Topic topic;
private Topic control;
private String url = "tcp://localhost:61616";
private int size = 256;
private int subscribers = 1;
private int remaining;
private int messages = 10000;
private long delay;
private int batch = 2000;
private byte[] payload;
public static void main(String[] argv) throws Exception {
TopicPublisher p = new TopicPublisher();
String[] unknown = CommandLineSupport.setOptions(p, argv);
if (unknown.length > 0) {
System.out.println("Unknown options: " + Arrays.toString(unknown));
System.exit(-1);
}
p.run();
}
private void run() throws Exception {
ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(url);
connection = factory.createConnection();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
topic = session.createTopic("VirtualTopic.Orders");
control = session.createTopic("VirtualTopic.control");
publisher = session.createProducer(topic);
publisher.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
payload = new byte[size];
for (int i = 0; i < size; i++) {
payload[i] = (byte)DATA[i % DATA.length];
}
session.createConsumer(control).setMessageListener(this);
connection.start();
long[] times = new long[batch];
for (int i = 0; i < batch; i++) {
if (i > 0) {
Thread.sleep(delay * 1000);
}
times[i] = batch(messages);
System.out.println("Batch " + (i + 1) + " of " + batch + " completed in " + times[i] + " ms.");
}
long min = min(times);
long max = max(times);
System.out.println("min: " + min + ", max: " + max + " avg: " + avg(times, min, max));
// request shutdown
publisher.send(session.createTextMessage("SHUTDOWN"));
connection.stop();
connection.close();
}
private long batch(int msgCount) throws Exception {
long start = System.currentTimeMillis();
remaining = subscribers;
publish();
waitForCompletion();
return System.currentTimeMillis() - start;
}
private void publish() throws Exception {
// send events
BytesMessage msg = session.createBytesMessage();
msg.writeBytes(payload);
for (int i = 0; i < messages; i++) {
publisher.send(msg);
if ((i + 1) % 1000 == 0) {
System.out.println("Sent " + (i + 1) + " messages");
}
}
// request report
publisher.send(session.createTextMessage("REPORT"));
}
private void waitForCompletion() throws Exception {
System.out.println("Waiting for completion...");
synchronized (mutex) {
while (remaining > 0) {
mutex.wait();
}
}
}
public void onMessage(Message message) {
synchronized (mutex) {
System.out.println("Received report " + getReport(message) + " " + --remaining + " remaining");
if (remaining == 0) {
mutex.notify();
}
}
}
Object getReport(Message m) {
try {
return ((TextMessage)m).getText();
} catch (JMSException e) {
e.printStackTrace(System.out);
return e.toString();
}
}
static long min(long[] times) {
long min = times.length > 0 ? times[0] : 0;
for (int i = 0; i < times.length; i++) {
min = Math.min(min, times[i]);
}
return min;
}
static long max(long[] times) {
long max = times.length > 0 ? times[0] : 0;
for (int i = 0; i < times.length; i++) {
max = Math.max(max, times[i]);
}
return max;
}
static long avg(long[] times, long min, long max) {
long sum = 0;
for (int i = 0; i < times.length; i++) {
sum += times[i];
}
sum -= min;
sum -= max;
return sum / times.length - 2;
}
public void setBatch(int batch) {
this.batch = batch;
}
public void setDelay(long delay) {
this.delay = delay;
}
public void setMessages(int messages) {
this.messages = messages;
}
public void setSize(int size) {
this.size = size;
}
public void setSubscribers(int subscribers) {
this.subscribers = subscribers;
}
public void setUrl(String url) {
this.url = url;
}
}
TopicListener:
/**
* 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.
*/
import java.util.Arrays;
import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import org.apache.activemq.ActiveMQConnectionFactory;
/**
* Use in conjunction with TopicPublisher to test the performance of ActiveMQ
* Topics.
*/
public class TopicListener implements MessageListener {
private Connection connection;
private MessageProducer producer;
private Session session;
private int count;
private long start;
private Topic topic;
private Topic control;
private String url = "tcp://localhost:61616";
public static void main(String[] argv) throws Exception {
TopicListener l = new TopicListener();
String[] unknown = CommandLineSupport.setOptions(l, argv);
if (unknown.length > 0) {
System.out.println("Unknown options: " + Arrays.toString(unknown));
System.exit(-1);
}
l.run();
}
public void run() throws JMSException {
ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(url);
connection = factory.createConnection();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
topic = session.createTopic("Consumer.A.VirtualTopic.Orders");
control = session.createTopic("Consumer.A.VirtualTopic.control");
MessageConsumer consumer = session.createConsumer(topic);
consumer.setMessageListener(this);
connection.start();
producer = session.createProducer(control);
System.out.println("Waiting for messages...");
}
private static boolean checkText(Message m, String s) {
try {
return m instanceof TextMessage && ((TextMessage)m).getText().equals(s);
} catch (JMSException e) {
e.printStackTrace(System.out);
return false;
}
}
public void onMessage(Message message) {
if (checkText(message, "SHUTDOWN")) {
try {
connection.close();
} catch (Exception e) {
e.printStackTrace(System.out);
}
} else if (checkText(message, "REPORT")) {
// send a report:
try {
long time = System.currentTimeMillis() - start;
String msg = "Received " + count + " in " + time + "ms";
producer.send(session.createTextMessage(msg));
} catch (Exception e) {
e.printStackTrace(System.out);
}
count = 0;
} else {
if (count == 0) {
start = System.currentTimeMillis();
}
if (++count % 1000 == 0) {
System.out.println("Received " + count + " messages.");
}
}
}
public void setUrl(String url) {
this.url = url;
}
}
Topics Browsing shows this:
<topic name="VirtualTopic.Orders"><stats size="0" consumerCount="0" enqueueCount="2001" dequeueCount="0"/></topic>
<topic name="Consumer.A.VirtualTopic.Orders"><stats size="0" consumerCount="1" enqueueCount="0" dequeueCount="0"/></topic>
The messages are not being consumed at all by the Listener. Where as , in the listener , If I specify the topic name as VirtualTopic.Orders then the listener is able to get the messages.
What I’m doing wrong here?
You have a subscription set up to a topic called “Consumer.A.VirtualTopic.Orders”. The subscription should be to a queue.