destinationcache.java

来自「OpenJMS是一个开源的Java Message Service API 1.」· Java 代码 · 共 127 行

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 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
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 * Copyright 2001-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: DestinationCache.java,v 1.3 2005/08/30 07:26:49 tanderson Exp $
 */

package org.exolab.jms.messagemgr;

import org.exolab.jms.client.JmsDestination;
import org.exolab.jms.gc.GarbageCollectable;


/**
 * A DestinationCache is used to cache messages for a particular destination.
 * <p/>
 * It implements {@link MessageManagerEventListener} in order to be notified of
 * messages being added to the {@link MessageManager}.
 * <p/>
 * A {@link ConsumerEndpoint} registers with a {@link DestinationCache} to
 * receive messages for a particular destination.
 *
 * @author <a href="mailto:[e-mail]">Jim Alateras</a>
 * @author <a href="mailto:[e-mail]">Tim Anderson</a>
 * @version $Revision: 1.3 $ $Date: 2005/08/30 07:26:49 $
 */
public interface DestinationCache extends MessageManagerEventListener,
        GarbageCollectable {

    /**
     * Returns the destination that messages are being cached for
     *
     * @return the destination that messages are being cached for
     */
    JmsDestination getDestination();

    /**
     * Register a consumer with this cache.
     *
     * @param consumer the message consumer for this destination
     * @return <code>true</code> if registered; otherwise <code>false</code>
     */
    boolean addConsumer(ConsumerEndpoint consumer);

    /**
     * Remove the consumer for the list of registered consumers.
     *
     * @param consumer the consumer to remove
     */
    void removeConsumer(ConsumerEndpoint consumer);

    /**
     * Determines if the cache has any consumers.
     *
     * @return <code>true</code> if the cache has consumers;
     * otherwise <code>false</code>
     */
    boolean hasConsumers();

    /**
     * Return a message handle back to the cache, to recover unsent
     * or unacknowledged messages.
     *
     * @param handle the message handle to return
     */
    void returnMessageHandle(MessageHandle handle);

    /**
     * Returns the number of messages in the cache.
     *
     * @return the number of messages in the cache
     */
    int getMessageCount();

    /**
     * Determines if this cache can be destroyed.
     *
     * @return <code>true</code> if the cache can be destroyed, otherwise
     *         <code>false</code>
     */
    boolean canDestroy();

    /**
     * Destroy this cache.
     */
    void destroy();

}