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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.activemq;

import javax.jms.JMSException;
import javax.jms.Topic;
import javax.jms.TopicSubscriber;

import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ConsumerId;

/**
 * A client uses a TopicSubscriber object to receive messages
 * that have been published to a topic. A TopicSubscriber object
 * is the publish/subscribe form of a message consumer. A 
 * MessageConsumer can be created by using 
 * Session.createConsumer.
 * 

*

* A TopicSession allows the creation of multiple * TopicSubscriber objects per topic. It will deliver each message for * a topic to each subscriber eligible to receive it. Each copy of the message * is treated as a completely separate message. Work done on one copy has no * effect on the others; acknowledging one does not acknowledge the others; one * message may be delivered immediately, while another waits for its subscriber * to process messages ahead of it. *

*

* Regular TopicSubscriber objects are not durable. They receive * only messages that are published while they are active. *

*

* Messages filtered out by a subscriber's message selector will never be * delivered to the subscriber. From the subscriber's perspective, they do not * exist. *

*

* In some cases, a connection may both publish and subscribe to a topic. The * subscriber NoLocal attribute allows a subscriber to inhibit * the delivery of messages published by its own connection. *

*

* If a client needs to receive all the messages published on a topic, * including the ones published while the subscriber is inactive, it uses a * durable TopicSubscriber. The JMS provider retains a record * of this durable subscription and insures that all messages from the topic's * publishers are retained until they are acknowledged by this durable * subscriber or they have expired. *

*

* Sessions with durable subscribers must always provide the same client * identifier. In addition, each client must specify a name that uniquely * identifies (within client identifier) each durable subscription it creates. * Only one session at a time can have a TopicSubscriber for a * particular durable subscription. *

*

* A client can change an existing durable subscription by creating a durable * TopicSubscriber with the same name and a new topic and/or * message selector. Changing a durable subscription is equivalent to * unsubscribing (deleting) the old one and creating a new one. *

*

* The unsubscribe method is used to delete a durable * subscription. The unsubscribe method can be used at the * Session or TopicSession level. This method * deletes the state being maintained on behalf of the subscriber by its * provider. *

*

* Creating a MessageConsumer provides the same features as * creating a TopicSubscriber. To create a durable subscriber, * use of Session.CreateDurableSubscriber is recommended. The * TopicSubscriber is provided to support existing code. * * @see javax.jms.Session#createConsumer * @see javax.jms.Session#createDurableSubscriber * @see javax.jms.TopicSession * @see javax.jms.TopicSession#createSubscriber * @see javax.jms.TopicSubscriber * @see javax.jms.MessageConsumer */ public class ActiveMQTopicSubscriber extends ActiveMQMessageConsumer implements TopicSubscriber { /** * @param theSession * @param value * @param dest * @param name * @param selector * @param cnum * @param noLocalValue * @param browserValue * @param asyncDispatch * @throws JMSException */ protected ActiveMQTopicSubscriber(ActiveMQSession theSession, ConsumerId consumerId, ActiveMQDestination dest, String name, String selector, int prefetch, int maximumPendingMessageCount, boolean noLocalValue, boolean browserValue, boolean asyncDispatch) throws JMSException { super(theSession, consumerId, dest, name, selector, prefetch, maximumPendingMessageCount, noLocalValue, browserValue, asyncDispatch, null); } /** * Gets the Topic associated with this subscriber. * * @return this subscriber's Topic * @throws JMSException if the JMS provider fails to get the topic for this topic * subscriber due to some internal error. */ public Topic getTopic() throws JMSException { checkClosed(); return (Topic) super.getDestination(); } /** * Gets the NoLocal attribute for this subscriber. The * default value for this attribute is false. * * @return true if locally published messages are being inhibited * @throws JMSException if the JMS provider fails to get the NoLocal * attribute for this topic subscriber due to some * internal error. */ public boolean getNoLocal() throws JMSException { checkClosed(); return super.isNoLocal(); } }





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