- /*
- * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package javax.jms;
-
- /** The <CODE>TopicRequestor</CODE> helper class simplifies
- * making service requests.
- *
- * <P>The <CODE>TopicRequestor</CODE> constructor is given a non-transacted
- * <CODE>TopicSession</CODE> and a destination <CODE>Topic</CODE>. It creates a
- * <CODE>TemporaryTopic</CODE> for the responses and provides a
- * <CODE>request</CODE> method that sends the request message and waits
- * for its reply.
- *
- * <P>This is a basic request/reply abstraction that should be sufficient
- * for most uses. JMS providers and clients are free to create more
- * sophisticated versions.
- *
- * @version 1.0 - 8 July 1998
- * @author Mark Hapner
- * @author Rich Burridge
- *
- * @see javax.jms.QueueRequestor
- */
-
- public class TopicRequestor {
-
- TopicSession session; // The topic session the topic belongs to.
- Topic topic; // The topic to perform the request/reply on.
- TemporaryTopic tempTopic;
- TopicPublisher publisher;
- TopicSubscriber subscriber;
-
-
- /** Constructor for the <CODE>TopicRequestor</CODE> class.
- *
- * <P>This implementation assumes the session parameter to be non-transacted,
- * with a delivery mode of either <CODE>AUTO_ACKNOWLEDGE</CODE> or
- * <CODE>DUPS_OK_ACKNOWLEDGE</CODE>.
- *
- * @param session the <CODE>TopicSession</CODE> the topic belongs to
- * @param topic the topic to perform the request/reply call on
- *
- * @exception JMSException if the JMS provider fails to create the
- * <CODE>TopicRequestor</CODE> due to some internal
- * error.
- * @exception InvalidDestinationException if an invalid topic is specified.
- */
-
- public
- TopicRequestor(TopicSession session, Topic topic) throws JMSException {
- this.session = session;
- this.topic = topic;
- tempTopic = session.createTemporaryTopic();
- publisher = session.createPublisher(topic);
- subscriber = session.createSubscriber(tempTopic);
- }
-
-
- /** Sends a request and waits for a reply. The temporary topic is used for
- * the <CODE>JMSReplyTo</CODE> destination; the first reply is returned,
- * and any following replies are discarded.
- *
- * @param message the message to send
- *
- * @return the reply message
- *
- * @exception JMSException if the JMS provider fails to complete the
- * request due to some internal error.
- */
-
- public Message
- request(Message message) throws JMSException {
- message.setJMSReplyTo(tempTopic);
- publisher.publish(message);
- return(subscriber.receive());
- }
-
-
- /** Closes the <CODE>TopicRequestor</CODE> and its session.
- *
- * <P>Since a provider may allocate some resources on behalf of a
- * <CODE>TopicRequestor</CODE> 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.
- *
- * <P>Note that this method closes the <CODE>TopicSession</CODE> object
- * passed to the <CODE>TopicRequestor</CODE> constructor.
- *
- * @exception JMSException if the JMS provider fails to close the
- * <CODE>TopicRequestor</CODE> due to some internal
- * error.
- */
-
- public void
- close() throws JMSException {
-
- // publisher and consumer created by constructor are implicitly closed.
- session.close();
- tempTopic.delete();
- }
- }