Package jakarta.jms

Class TopicRequestor

java.lang.Object

jakarta.jms.TopicRequestor

public class TopicRequestor
extends Object

The TopicRequestor helper class simplifies making service requests.

The TopicRequestor constructor is given a non-transacted TopicSession and a destination Topic. It creates a TemporaryTopic for the responses and provides a request method that sends the request message and waits for its reply.

This is a very basic request/reply abstraction which assumes the session is non-transacted with a delivery mode of either AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE. It is expected that most applications will create less basic implementations.

Since:

JMS 1.0

Version:

Jakarta Messaging 2.0

See Also:

• QueueRequestor

Constructor Summary

Constructors

Constructor	Description
TopicRequestor(TopicSession session, Topic topic)	Constructor for the TopicRequestor class.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the TopicRequestor and its session.
Message	request(Message message)	Sends a request and waits for a reply.

Methods inherited from class java.lang.Object

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

Constructor Details

TopicRequestor

public TopicRequestor(TopicSession session,
 Topic topic)
               throws JMSException

Constructor for the TopicRequestor class.

This implementation assumes the session parameter to be non-transacted, with a delivery mode of either AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE.

Parameters:

session - the TopicSession the topic belongs to

topic - the topic to perform the request/reply call on

Throws:

JMSException - if the Jakarta Messaging provider fails to create the TopicRequestor due to some internal error.

InvalidDestinationException - if an invalid topic is specified.

Method Details

request

public Message request(Message message)
                throws JMSException

Sends a request and waits for a reply. The temporary topic is used for the JMSReplyTo destination; the first reply is returned, and any following replies are discarded.

Parameters:

message - the message to send

Returns:

the reply message

Throws:

JMSException - if the Jakarta Messaging provider fails to complete the request due to some internal error.

close

public void close()
           throws JMSException

Closes the TopicRequestor and its session.

Since a provider may allocate some resources on behalf of a TopicRequestor outside the Java virtual machine, clients should close them when they are not needed. Relying on garbage collection to eventually reclaim these resources may not be timely enough.

Note that this method closes the TopicSession object passed to the TopicRequestor constructor.

Throws:

JMSException - if the Jakarta Messaging provider fails to close the TopicRequestor due to some internal error.