jakarta.jms.QueueBrowser Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2017 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.jms;
import java.util.Enumeration;
/**
* A client uses a {@code QueueBrowser} object to look at messages on a queue without removing them.
*
*
* The {@code getEnumeration} method returns a {@code 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 Jakarta Messaging 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 message must not be returned by a {@code QueueBrowser} before its delivery time has been reached.
*
*
* A {@code QueueBrowser} can be created from either a {@code Session} or a {@code QueueSession}.
*
* @see jakarta.jms.Session#createBrowser
* @see jakarta.jms.QueueSession#createBrowser
* @see jakarta.jms.QueueReceiver
*
* @version Jakarta Messaging 2.0
* @since JMS 1.0
*/
public interface QueueBrowser extends AutoCloseable {
/**
* Gets the queue associated with this queue browser.
*
* @return the queue
*
* @exception JMSException if the Jakarta Messaging provider fails to get the queue associated with this browser due to some internal
* error.
*/
Queue getQueue() throws JMSException;
/**
* Gets this queue browser's message selector expression.
*
* @return 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)
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message selector for this browser due to some internal
* error.
*/
String getMessageSelector() throws JMSException;
/**
* Gets an enumeration for browsing the current queue messages in the order they would be received.
*
* @return an enumeration for browsing the messages
*
* @exception JMSException if the Jakarta Messaging provider fails to get the enumeration for this browser due to some internal error.
*/
Enumeration getEnumeration() throws JMSException;
/**
* Closes the {@code 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.
*
* @exception JMSException if the Jakarta Messaging provider fails to close this browser due to some internal error.
*/
@Override
void close() throws JMSException;
}