| /** |
| * 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 <CODE>TopicSubscriber</CODE> object to receive messages |
| * that have been published to a topic. A <CODE>TopicSubscriber</CODE> object |
| * is the publish/subscribe form of a message consumer. A <CODE> |
| * MessageConsumer</CODE> can be created by using <CODE> |
| * Session.createConsumer</CODE>. |
| * <p/> |
| * <P> |
| * A <CODE>TopicSession</CODE> allows the creation of multiple <CODE> |
| * TopicSubscriber</CODE> 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. |
| * <p/> |
| * <P> |
| * Regular <CODE>TopicSubscriber</CODE> objects are not durable. They receive |
| * only messages that are published while they are active. |
| * <p/> |
| * <P> |
| * 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. |
| * <p/> |
| * <P> |
| * In some cases, a connection may both publish and subscribe to a topic. The |
| * subscriber <CODE>NoLocal</CODE> attribute allows a subscriber to inhibit |
| * the delivery of messages published by its own connection. |
| * <p/> |
| * <P> |
| * 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 <CODE>TopicSubscriber</CODE>. 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. |
| * <p/> |
| * <P> |
| * 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 <CODE>TopicSubscriber</CODE> for a |
| * particular durable subscription. |
| * <p/> |
| * <P> |
| * A client can change an existing durable subscription by creating a durable |
| * <CODE>TopicSubscriber</CODE> 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. |
| * <p/> |
| * <P> |
| * The <CODE>unsubscribe</CODE> method is used to delete a durable |
| * subscription. The <CODE>unsubscribe</CODE> method can be used at the |
| * <CODE>Session</CODE> or <CODE>TopicSession</CODE> level. This method |
| * deletes the state being maintained on behalf of the subscriber by its |
| * provider. |
| * <p/> |
| * <P> |
| * Creating a <CODE>MessageConsumer</CODE> provides the same features as |
| * creating a <CODE>TopicSubscriber</CODE>. To create a durable subscriber, |
| * use of <CODE>Session.CreateDurableSubscriber</CODE> is recommended. The |
| * <CODE>TopicSubscriber</CODE> 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 <CODE>Topic</CODE> associated with this subscriber. |
| * |
| * @return this subscriber's <CODE>Topic</CODE> |
| * @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 <CODE>NoLocal</CODE> 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 <CODE>NoLocal |
| * </CODE> attribute for this topic subscriber due to some |
| * internal error. |
| */ |
| |
| public boolean getNoLocal() throws JMSException { |
| checkClosed(); |
| return super.isNoLocal(); |
| } |
| } |