org.hawkular.bus.common.consumer

Class AbstractBasicMessageListener<T extends BasicMessage>

java.lang.Object

org.hawkular.bus.common.consumer.AbstractBasicMessageListener<T>

All Implemented Interfaces:

javax.jms.MessageListener

Direct Known Subclasses:

BasicMessageListener, RPCBasicMessageListener

public abstract class AbstractBasicMessageListener<T extends BasicMessage>
extends Object
implements javax.jms.MessageListener

A message listener that expects to receive a JSON-encoded BasicMessage or one of its subclasses; the JSON decoding is handled for you. Subclasses will typically override AbstractBasicMessageListener(Class) or determineBasicMessageClass() unless either (a) the subclass hierarchy has generic types that are specific enough for reflection to determine the type of BasicMessage being listened for or (b) the message type being listened for is BasicMessage and not one of its subclasses.

Constructor Summary

Constructors

Modifier	Constructor and Description
	AbstractBasicMessageListener()
protected	AbstractBasicMessageListener(Class<T> jsonDecoderRing) If a subclass knows the type and can give it to us, that will be the type used to decode JSON strings into that message type.

Method Summary

Modifier and Type	Method and Description
protected Class<T>	determineBasicMessageClass() In order to decode the JSON, we need the class representation of the basic message type.
protected Class<T>	getBasicMessageClass()
protected T	getBasicMessageFromMessage(javax.jms.Message message) Given the Message received over the wire, convert it to our T representation of the message.
ConsumerConnectionContext	getConsumerConnectionContext() When this listener is attached to a consumer, this field should be filled in to allow the listener to perform other tasks it needs which might require access to the context.
protected org.jboss.logging.Logger	getLog()
void	setConsumerConnectionContext(ConsumerConnectionContext consumerConnectionContext)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.jms.MessageListener

onMessage

Constructor Detail

AbstractBasicMessageListener

public AbstractBasicMessageListener()

AbstractBasicMessageListener

protected AbstractBasicMessageListener(Class<T> jsonDecoderRing)

If a subclass knows the type and can give it to us, that will be the type used to decode JSON strings into that message type. If this constructor is not used by subclasses, typically those subclasses will need to override determineBasicMessageClass() unless BasicMessage is the message type that subclass wants to explicitly use (as opposed to a subclass of BasicMessage).

Parameters:

jsonDecoderRing - the class representation of the generic type T

Method Detail

getConsumerConnectionContext

public ConsumerConnectionContext getConsumerConnectionContext()

When this listener is attached to a consumer, this field should be filled in to allow the listener to perform other tasks it needs which might require access to the context.

Returns:

the consumer context this listener is associated with, or null if not associated with a consumer yet

setConsumerConnectionContext

public void setConsumerConnectionContext(ConsumerConnectionContext consumerConnectionContext)

getBasicMessageFromMessage

protected T getBasicMessageFromMessage(javax.jms.Message message)

Given the Message received over the wire, convert it to our T representation of the message.

Parameters:

message - the over-the-wire message

Returns:

the message as a object T, or null if we should not or cannot process the message

getBasicMessageClass

protected Class<T> getBasicMessageClass()

determineBasicMessageClass

protected Class<T> determineBasicMessageClass()

In order to decode the JSON, we need the class representation of the basic message type. This method uses reflection to try to get that type. Subclasses can override this if they want to provide the class representation themselves (e.g. in case the reflection cannot get it). Alternatively, subclasses can utilize the constructor AbstractBasicMessageListener(Class) to tell this object what the class of T is.

Returns:

class of T

getLog

protected org.jboss.logging.Logger getLog()

Returns:

logger for subclasses to use to log ad-hoc debug or trace messages