Package com.mayam.wf.mq

Interface Mq

public interface Mq

Message queue abstraction with retry and replay functionality.

  mq.attachListener(MqDestination.of("queue://mayam.task.test"), new Mq.Listener() {
     public void onMessage(MqMessage message) throws InvalidMessageException {
      final AttributeMap subject = message.getSubject();
      final Long taskId = subject.getAttribute(Attribute.TASK_ID);
      ...
    }
  });

  while (isRunning()) {
    mq.listen(ListenIntensity.RELAXED);
  }

  mq.shutdownConsumers();
 

NOTE: Only one listener per destination is currently fully supported. Acknowledge messages are sent as soon a related listener has successfully processed (and possibly ignored) a message.

Author:

Markus Mårtensson

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	Mq.Detachable	Returned by attachListener(MqDestination, Listener), its Mq.Detachable.detach() method allows a callback to be removed.
static interface	Mq.Listener	Callback for use with attachListener(MqDestination, Listener).
static enum	Mq.ListenIntensity	The intensity with which listening should be performed.

Method Summary

Modifier and Type	Method	Description
Mq.Detachable	attachListener(MqDestination source, Mq.Listener callback)	Attach a listener to a specified queue or topic.
void	listen()	Listen for messages using default intensity, passing them to all registered Mq.Listener callbacks.
void	listen(Mq.ListenIntensity intensity)	Listen for messages using specified intensity, passing them to all registered Mq.Listener callbacks.
void	ping()	Sends a ping message to Mq to make sure it's alive
void	send(MqDestination destination, MqMessage msg)	Send a MqMessage to a given queue or topic.
void	sendVolatile(MqDestination destination, MqMessage msg)	Send a MqMessage to a given queue or topic.
void	shutdownConsumers()	Shuts down connection and cleans up any objects related to receiving messages within the current thread.
void	shutdownProducers()	Shuts down connection and cleans up any objects related to sending messages within the current thread.

Method Details

send

void send(MqDestination destination,
 MqMessage msg)
   throws MqException

Send a MqMessage to a given queue or topic. If the message could not be sent, it will be made available via the ReplayStore.

Parameters:

destination - queue or topic to use as destination.

msg - the message to be sent.

Throws:

MqException - if the message could not be sent.

sendVolatile

void sendVolatile(MqDestination destination,
 MqMessage msg)

Send a MqMessage to a given queue or topic. If the message could not be sent, it will be discarded and no exception will be thrown.

Parameters:

destination - queue or topic to use as destination.

msg - the message to be sent.

listen

void listen()

Listen for messages using default intensity, passing them to all registered Mq.Listener callbacks.

listen

void listen(Mq.ListenIntensity intensity)

Listen for messages using specified intensity, passing them to all registered Mq.Listener callbacks.

Parameters:

intensity -

attachListener

Mq.Detachable attachListener(MqDestination source,
 Mq.Listener callback)

Attach a listener to a specified queue or topic.

Parameters:

source - queue or topic to listen to.

callback - called by listen() when a matching message is found.

Returns:

a Mq.Detachable object allowing the listener to detach itself.

shutdownProducers

void shutdownProducers()

Shuts down connection and cleans up any objects related to sending messages within the current thread.

shutdownConsumers

void shutdownConsumers()

Shuts down connection and cleans up any objects related to receiving messages within the current thread.

ping

void ping()
   throws MqException

Sends a ping message to Mq to make sure it's alive

Throws:

MqException