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.

Version:

1.0 - 13 August 1998

Author:

Mark Hapner, Rich Burridge

See Also:

QueueSession.createBrowser(Queue), QueueSession.createBrowser(Queue, String), 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.