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QueueBrowser (Java 2 Platform Ent. Ed. v1.4) - Java Platform, Enterprise Edition v1.4 API Specifications

JavaTM 2 Platform
Ent. Ed. v1.4

javax.jms
Interface QueueBrowser


public interface QueueBrowser

A client uses a QueueBrowser object to look at messages on a queue without removing them.

The getEnumeration method returns a java.util.Enumeration that is used to scan the queue's messages. It may be an enumeration of the entire content of a queue, or it may contain only the messages matching a message selector.

Messages may be arriving and expiring while the scan is done. The JMS API does not require the content of an enumeration to be a static snapshot of queue content. Whether these changes are visible or not depends on the JMS provider.

A QueueBrowser can be created from either a Session or a QueueSession.

Version:
1.1 April 9, 2002
Author:
Mark Hapner, Rich Burridge, Kate Stout
See Also:
Session.createBrowser(javax.jms.Queue), QueueSession.createBrowser(javax.jms.Queue), QueueReceiver

Method Summary
 void close()
          Closes the QueueBrowser.
 Enumeration getEnumeration()
          Gets an enumeration for browsing the current queue messages in the order they would be received.
 String getMessageSelector()
          Gets this queue browser's message selector expression.
 Queue getQueue()
          Gets the queue associated with this queue browser.
 

Method Detail

getQueue

public Queue getQueue()
               throws JMSException
Gets the queue associated with this queue browser.

Returns:
the queue
Throws:
JMSException - if the JMS provider fails to get the queue associated with this browser due to some internal error.

getMessageSelector

public String getMessageSelector()
                          throws JMSException
Gets this queue browser's message selector expression.

Returns:
this queue browser's message selector, or null if no message selector exists for the message consumer (that is, if the message selector was not set or was set to null or the empty string)
Throws:
JMSException - if the JMS provider fails to get the message selector for this browser due to some internal error.

getEnumeration

public Enumeration getEnumeration()
                           throws JMSException
Gets an enumeration for browsing the current queue messages in the order they would be received.

Returns:
an enumeration for browsing the messages
Throws:
JMSException - if the JMS provider fails to get the enumeration for this browser due to some internal error.

close

public void close()
           throws JMSException
Closes the QueueBrowser.

Since a provider may allocate some resources on behalf of a QueueBrowser 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.

Throws:
JMSException - if the JMS provider fails to close this browser due to some internal error.

JavaTM 2 Platform
Ent. Ed. v1.4

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Copyright 2003 Sun Microsystems, Inc. All rights reserved.