Signal a rollback from a JMS MessageListener
I've been working with JMS and ActiveMQ. Everything is working wonders. I am not using spring, nor can I.
The interface javax.jms.MessageListener
has only one method, onMessage
. From within a implementation, there is a chance an exception will be thrown. If in fact an exception gets thrown, then I say the message wasn't properly processed and needs to be re-tried. So, I need ActiveMQ to wait for a little while and then, retry. i.e. I need the thrown exception to rollback the JMS transaction.
How can I accomplish such a behaviour?
Maybe there is some configuration in ActiveMQ I wasn't able to find.
Or... maybe could do away with registering MessageListener
s to consumers and consume the messages myself, in a a loop like:
while (true) {
// ... some administrative stuff like ...
session = connection.createSesstion(true, SESSION_TRANSACTED)
try {
Message m = receiver.receive(queue, 1000L);
theMessa开发者_开发百科geListener.onMessage(m);
session.commit();
} catch (Exception e) {
session.rollback();
Thread.sleep(someTimeDefinedSomewhereElse);
}
// ... some more administrative stuff
}
in a couple of threads, instead of registering the listener.
Or... I could somehow decorate/AOP/byte-manipulate the MessageListener
s to do this themselves.
What route would you take and why?
note: I don't have full control over the MessageListener
s code.
EDIT A test for proof of concept:
@Test
@Ignore("Interactive test, just a proof of concept")
public void transaccionConListener() throws Exception {
final AtomicInteger atomicInteger = new AtomicInteger(0);
BrokerService brokerService = new BrokerService();
String bindAddress = "vm://localhost";
brokerService.addConnector(bindAddress);
brokerService.setPersistenceAdapter(new MemoryPersistenceAdapter());
brokerService.setUseJmx(false);
brokerService.start();
ActiveMQConnectionFactory activeMQConnectionFactory = new ActiveMQConnectionFactory(bindAddress);
RedeliveryPolicy redeliveryPolicy = new RedeliveryPolicy();
redeliveryPolicy.setInitialRedeliveryDelay(500);
redeliveryPolicy.setBackOffMultiplier(2);
redeliveryPolicy.setUseExponentialBackOff(true);
redeliveryPolicy.setMaximumRedeliveries(2);
activeMQConnectionFactory.setRedeliveryPolicy(redeliveryPolicy);
activeMQConnectionFactory.setUseRetroactiveConsumer(true);
activeMQConnectionFactory.setClientIDPrefix("ID");
PooledConnectionFactory pooledConnectionFactory = new PooledConnectionFactory(activeMQConnectionFactory);
pooledConnectionFactory.start();
Connection connection = pooledConnectionFactory.createConnection();
Session session = connection.createSession(false, Session.DUPS_OK_ACKNOWLEDGE);
Queue helloQueue = session.createQueue("Hello");
MessageConsumer consumer = session.createConsumer(helloQueue);
consumer.setMessageListener(new MessageListener() {
@Override
public void onMessage(Message message) {
TextMessage textMessage = (TextMessage) message;
try {
switch (atomicInteger.getAndIncrement()) {
case 0:
System.out.println("OK, first message received " + textMessage.getText());
message.acknowledge();
break;
case 1:
System.out.println("NOPE, second must be retried " + textMessage.getText());
throw new RuntimeException("I failed, aaaaah");
case 2:
System.out.println("OK, second message received " + textMessage.getText());
message.acknowledge();
}
} catch (JMSException e) {
e.printStackTrace(System.out);
}
}
});
connection.start();
{
// A client sends two messages...
Connection connection1 = pooledConnectionFactory.createConnection();
Session session1 = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
connection1.start();
MessageProducer producer = session1.createProducer(helloQueue);
producer.send(session1.createTextMessage("Hello World 1"));
producer.send(session1.createTextMessage("Hello World 2"));
producer.close();
session1.close();
connection1.stop();
connection1.close();
}
JOptionPane.showInputDialog("I will wait, you watch the log...");
consumer.close();
session.close();
connection.stop();
connection.close();
pooledConnectionFactory.stop();
brokerService.stop();
assertEquals(3, atomicInteger.get());
}
If you want to use SESSION_TRANSACTED as your acknowledgement mode, then you need to setup a RedeliveryPolicy on your Connection/ConnectionFactory. This page on ActiveMQ's website also contains some good info for what you might need to do.
Since you aren't using Spring, you can setup a RedeliveryPolicy with something similar to the following code (taken from one of the above links):
RedeliveryPolicy policy = connection.getRedeliveryPolicy();
policy.setInitialRedeliveryDelay(500);
policy.setBackOffMultiplier(2);
policy.setUseExponentialBackOff(true);
policy.setMaximumRedeliveries(2);
Edit Taking your code snippet added to the answer, the following shows how this works with transactions. Try this code with the Session.rollback() method commented out and you'll see that using SESION_TRANSACTED and Session.commit/rollback works as expected:
@Test
public void test() throws Exception {
final AtomicInteger atomicInteger = new AtomicInteger(0);
BrokerService brokerService = new BrokerService();
String bindAddress = "vm://localhost";
brokerService.addConnector(bindAddress);
brokerService.setPersistenceAdapter(new MemoryPersistenceAdapter());
brokerService.setUseJmx(false);
brokerService.start();
ActiveMQConnectionFactory activeMQConnectionFactory = new ActiveMQConnectionFactory(bindAddress);
RedeliveryPolicy redeliveryPolicy = new RedeliveryPolicy();
redeliveryPolicy.setInitialRedeliveryDelay(500);
redeliveryPolicy.setBackOffMultiplier(2);
redeliveryPolicy.setUseExponentialBackOff(true);
redeliveryPolicy.setMaximumRedeliveries(2);
activeMQConnectionFactory.setRedeliveryPolicy(redeliveryPolicy);
activeMQConnectionFactory.setUseRetroactiveConsumer(true);
activeMQConnectionFactory.setClientIDPrefix("ID");
PooledConnectionFactory pooledConnectionFactory = new PooledConnectionFactory(activeMQConnectionFactory);
pooledConnectionFactory.start();
Connection connection = pooledConnectionFactory.createConnection();
final Session session = connection.createSession(true, Session.SESSION_TRANSACTED);
Queue helloQueue = session.createQueue("Hello");
MessageConsumer consumer = session.createConsumer(helloQueue);
consumer.setMessageListener(new MessageListener() {
public void onMessage(Message message) {
TextMessage textMessage = (TextMessage) message;
try {
switch (atomicInteger.getAndIncrement()) {
case 0:
System.out.println("OK, first message received " + textMessage.getText());
session.commit();
break;
case 1:
System.out.println("NOPE, second must be retried " + textMessage.getText());
session.rollback();
throw new RuntimeException("I failed, aaaaah");
case 2:
System.out.println("OK, second message received " + textMessage.getText());
session.commit();
}
} catch (JMSException e) {
e.printStackTrace(System.out);
}
}
});
connection.start();
{
// A client sends two messages...
Connection connection1 = pooledConnectionFactory.createConnection();
Session session1 = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
connection1.start();
MessageProducer producer = session1.createProducer(helloQueue);
producer.send(session1.createTextMessage("Hello World 1"));
producer.send(session1.createTextMessage("Hello World 2"));
producer.close();
session1.close();
connection1.stop();
connection1.close();
}
JOptionPane.showInputDialog("I will wait, you watch the log...");
consumer.close();
session.close();
connection.stop();
connection.close();
pooledConnectionFactory.stop();
assertEquals(3, atomicInteger.get());
}
}
You need to set the acknowledgment mode to Session.CLIENT_ACKNOWLEDGE, the client acknowledges a consumed message by calling the message's acknowledge method.
QueueSession session = connection.createQueueSession(false, Session.CLIENT_ACKNOWLEDGE);
Then, after processing the message to need to call the Message.acknowledge() method in order to remove that message.
Message message = ...;
// Processing message
message.acknowledge();
A little late, but here goes -
I would not use a MessageListener
but rather a global pools to manage listening and processing.
ListeningPool -> listener -> submit processing task -> ProcessingPool -> execute and acknowledge or close without acknowledgment.
- Maintain 2 thread pools, one for listeners and one for processors.
- Have a listening Runnable implementation that listens to a queue in a while true loop, and consumer.receive(timeout) method. In the finally block, close connection, session and consumer if there was no message received. If a message is received, submit a task to processing pool with all the conn, session, message and consumer arguments.
- Have a processing implementation that takes in the message, connection, session and consumer. Do your processing and acknowledge if all ok. If not, close without acknowledgement. This would trigger a redelivery according to your server's redelivery policy.
- Initialize your listening pool with all the Listener Tasks, listening for messages, each for one queue. Initialize your processing pool with parameters acceptable to your application runtime.
public class CustomMessageListener implements Runnable {
private ConnectionFactory connectionFactory;
private MessageProcessor processor;
private long backOff;
private boolean stopped = false;
private Executor processPool;
public CustomMessageListener(ConnectionFactory connectionFactory,
long backOff, MessageProcessor processor, Executor processPool) {
this.connectionFactory = connectionFactory;
this.backOff = backOff;
this.processor = processor;
this.processPool = processPool;
}
@Override
public void run() {
while (!stopped) {
listen();
}
}
public void stop() {
this.stopped = true;
}
public void listen() {
Connection c = null;
Session s = null;
MessageConsumer consumer = null;
boolean received = false;
try {
c = connectionFactory.createConnection();
s = c.createSession(false, Session.CLIENT_ACKNOWLEDGE);
consumer = s.createConsumer(...);
Message message = consumer.receive(backOff); // waits maximum backOff ms for a message
if (message != null) {
received = true;
// submit a task to processing pool...
executor.submit(processor.process(message, s, consumer, c));
}
} catch (JMSException ex) {
// log your exception
} finally {
if (!received) {
// close conn, session, consumer
}
}
}
}
public class MessageProcessor {
public Runnable process(Message msg, Session s, MessageConsumer consumer, Connection conn) {
return () - > {
try {
//do your processing
msg.acknowledge(); // done
} catch (JMSException ex) {
// log your exception
} finally {
// close your resources
}
};
}
}
You can call stop()
to stop listening for more messages, for a graceful shutdown. Include a queueName
in the constructor to listen for a particular queue.
If your session is transacted,then "acknowledgeMode" is ignored anyways..So, just leave your session transacted and use session.rollback and session.commit to commit or rollback your transaction.
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