ActiveMQ example source code file (TopicRegion.java)

This example ActiveMQ source code file (TopicRegion.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

activemqdestination, consumerinfo, consumerinfo, durabletopicsubscription, durabletopicsubscription, exception, iterator, jmsexception, jmsexception, override, subscriptionkey, subscriptionkey, threading, threads, topic, topicsubscription, util

The ActiveMQ TopicRegion.java source code

/**
 * 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.broker.region;

import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import javax.jms.InvalidDestinationException;
import javax.jms.JMSException;
import org.apache.activemq.advisory.AdvisorySupport;
import org.apache.activemq.broker.ConnectionContext;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.command.ActiveMQDestination;
import org.apache.activemq.command.ConnectionId;
import org.apache.activemq.command.ConsumerId;
import org.apache.activemq.command.ConsumerInfo;
import org.apache.activemq.command.RemoveSubscriptionInfo;
import org.apache.activemq.command.SessionId;
import org.apache.activemq.command.SubscriptionInfo;
import org.apache.activemq.store.TopicMessageStore;
import org.apache.activemq.thread.TaskRunnerFactory;
import org.apache.activemq.usage.SystemUsage;
import org.apache.activemq.util.LongSequenceGenerator;
import org.apache.activemq.util.SubscriptionKey;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 */
public class TopicRegion extends AbstractRegion {
    private static final Logger LOG = LoggerFactory.getLogger(TopicRegion.class);
    protected final ConcurrentHashMap<SubscriptionKey, DurableTopicSubscription> durableSubscriptions = new ConcurrentHashMap();
    private final LongSequenceGenerator recoveredDurableSubIdGenerator = new LongSequenceGenerator();
    private final SessionId recoveredDurableSubSessionId = new SessionId(new ConnectionId("OFFLINE"), recoveredDurableSubIdGenerator.getNextSequenceId());
    private boolean keepDurableSubsActive;

    public TopicRegion(RegionBroker broker, DestinationStatistics destinationStatistics, SystemUsage memoryManager, TaskRunnerFactory taskRunnerFactory,
                       DestinationFactory destinationFactory) {
        super(broker, destinationStatistics, memoryManager, taskRunnerFactory, destinationFactory);

    }

    @Override
    public Subscription addConsumer(ConnectionContext context, ConsumerInfo info) throws Exception {
        if (info.isDurable()) {
            ActiveMQDestination destination = info.getDestination();
            if (!destination.isPattern()) {
                // Make sure the destination is created.
                lookup(context, destination,true);
            }
            String clientId = context.getClientId();
            String subscriptionName = info.getSubscriptionName();
            SubscriptionKey key = new SubscriptionKey(clientId, subscriptionName);
            DurableTopicSubscription sub = durableSubscriptions.get(key);
            if (sub != null) {
                if (sub.isActive()) {
                    throw new JMSException("Durable consumer is in use for client: " + clientId + " and subscriptionName: " + subscriptionName);
                }
                // Has the selector changed??
                if (hasDurableSubChanged(info, sub.getConsumerInfo())) {
                    // Remove the consumer first then add it.
                    durableSubscriptions.remove(key);
                    synchronized (destinationsMutex) {
                        for (Iterator<Destination> iter = destinations.values().iterator(); iter.hasNext();) {
                            Destination dest = iter.next();
                            //Account for virtual destinations
                            if (dest instanceof Topic){
                                Topic topic = (Topic)dest;
                                topic.deleteSubscription(context, key);
                            }
                        }
                    }
                    super.removeConsumer(context, sub.getConsumerInfo());
                    super.addConsumer(context, info);
                    sub = durableSubscriptions.get(key);
                } else {
                    // Change the consumer id key of the durable sub.
                    if (sub.getConsumerInfo().getConsumerId() != null) {
                        subscriptions.remove(sub.getConsumerInfo().getConsumerId());
                    }
                    subscriptions.put(info.getConsumerId(), sub);
                }
            } else {
                super.addConsumer(context, info);
                sub = durableSubscriptions.get(key);
                if (sub == null) {
                    throw new JMSException("Cannot use the same consumerId: " + info.getConsumerId() + " for two different durable subscriptions clientID: " + key.getClientId()
                                           + " subscriberName: " + key.getSubscriptionName());
                }
            }
            sub.activate(usageManager, context, info);
            return sub;
        } else {
            return super.addConsumer(context, info);
        }
    }

    @Override
    public void removeConsumer(ConnectionContext context, ConsumerInfo info) throws Exception {
        if (info.isDurable()) {

            SubscriptionKey key = new SubscriptionKey(context.getClientId(), info.getSubscriptionName());
            DurableTopicSubscription sub = durableSubscriptions.get(key);
            if (sub != null) {
                sub.deactivate(keepDurableSubsActive);
            }

        } else {
            super.removeConsumer(context, info);
        }
    }

    @Override
    public void removeSubscription(ConnectionContext context, RemoveSubscriptionInfo info) throws Exception {
        SubscriptionKey key = new SubscriptionKey(info.getClientId(), info.getSubscriptionName());
        DurableTopicSubscription sub = durableSubscriptions.remove(key);
        if (sub == null) {
            throw new InvalidDestinationException("No durable subscription exists for: " + info.getSubscriptionName());
        }
        if (sub.isActive()) {
            throw new JMSException("Durable consumer is in use");
        }

        synchronized (destinationsMutex) {
            for (Iterator<Destination> iter = destinations.values().iterator(); iter.hasNext();) {
            	Destination dest = iter.next();
            	//Account for virtual destinations
            	if (dest instanceof Topic){
            	    Topic topic = (Topic)dest;
            	    topic.deleteSubscription(context, key);
            	}
            }
        }
        if (subscriptions.get(sub.getConsumerInfo()) != null) {
            super.removeConsumer(context, sub.getConsumerInfo());
        } else {
            // try destroying inactive subscriptions
            destroySubscription(sub);
        }
    }

    @Override
    public String toString() {
        return "TopicRegion: destinations=" + destinations.size() + ", subscriptions=" + subscriptions.size() + ", memory=" + usageManager.getMemoryUsage().getPercentUsage() + "%";
    }

    @Override
    protected List<Subscription> addSubscriptionsForDestination(ConnectionContext context, Destination dest) throws Exception {
        List<Subscription> rc = super.addSubscriptionsForDestination(context, dest);
        Set<Subscription> dupChecker = new HashSet(rc);

        TopicMessageStore store = (TopicMessageStore)dest.getMessageStore();
        // Eagerly recover the durable subscriptions
        if (store != null) {
            SubscriptionInfo[] infos = store.getAllSubscriptions();
            for (int i = 0; i < infos.length; i++) {

                SubscriptionInfo info = infos[i];
                LOG.debug("Restoring durable subscription: " + info);
                SubscriptionKey key = new SubscriptionKey(info);

                // A single durable sub may be subscribing to multiple topics.
                // so it might exist already.
                DurableTopicSubscription sub = durableSubscriptions.get(key);
                ConsumerInfo consumerInfo = createInactiveConsumerInfo(info);
                if (sub == null) {
                    ConnectionContext c = new ConnectionContext();
                    c.setBroker(context.getBroker());
                    c.setClientId(key.getClientId());
                    c.setConnectionId(consumerInfo.getConsumerId().getParentId().getParentId());
                    sub = (DurableTopicSubscription)createSubscription(c, consumerInfo);
                }

                if (dupChecker.contains(sub)) {
                    continue;
                }

                dupChecker.add(sub);
                rc.add(sub);
                dest.addSubscription(context, sub);
            }

            // Now perhaps there other durable subscriptions (via wild card)
            // that would match this destination..
            durableSubscriptions.values();
            for (Iterator<DurableTopicSubscription> iterator = durableSubscriptions.values().iterator(); iterator.hasNext();) {
                DurableTopicSubscription sub = iterator.next();
                // Skip over subscriptions that we allready added..
                if (dupChecker.contains(sub)) {
                    continue;
                }

                if (sub.matches(dest.getActiveMQDestination())) {
                    rc.add(sub);
                    dest.addSubscription(context, sub);
                }
            }
        }
        return rc;
    }

    private ConsumerInfo createInactiveConsumerInfo(SubscriptionInfo info) {
        ConsumerInfo rc = new ConsumerInfo();
        rc.setSelector(info.getSelector());
        rc.setSubscriptionName(info.getSubscriptionName());
        rc.setDestination(info.getSubscribedDestination());
        rc.setConsumerId(createConsumerId());
        return rc;
    }

    private ConsumerId createConsumerId() {
        return new ConsumerId(recoveredDurableSubSessionId, recoveredDurableSubIdGenerator.getNextSequenceId());
    }

    protected void configureTopic(Topic topic, ActiveMQDestination destination) {
        if (broker.getDestinationPolicy() != null) {
            PolicyEntry entry = broker.getDestinationPolicy().getEntryFor(destination);
            if (entry != null) {
                entry.configure(broker,topic);
            }
        }
    }

    @Override
    protected Subscription createSubscription(ConnectionContext context, ConsumerInfo info) throws JMSException {
        ActiveMQDestination destination = info.getDestination();
        
        if (info.isDurable()) {
            if (AdvisorySupport.isAdvisoryTopic(info.getDestination())) {
                throw new JMSException("Cannot create a durable subscription for an advisory Topic");
            }
            SubscriptionKey key = new SubscriptionKey(context.getClientId(), info.getSubscriptionName());
            DurableTopicSubscription sub = durableSubscriptions.get(key);
            
            if (sub == null) {
                
                sub = new DurableTopicSubscription(broker, usageManager, context, info, keepDurableSubsActive);

                if (destination != null && broker.getDestinationPolicy() != null) {
                    PolicyEntry entry = broker.getDestinationPolicy().getEntryFor(destination);
                    if (entry != null) {
                        entry.configure(broker, usageManager, sub);
                    }
                }
                durableSubscriptions.put(key, sub);
            } else {
                throw new JMSException("That durable subscription is already active.");
            }
            return sub;
        }
        try {
            TopicSubscription answer = new TopicSubscription(broker, context, info, usageManager);
            // lets configure the subscription depending on the destination
            if (destination != null && broker.getDestinationPolicy() != null) {
                PolicyEntry entry = broker.getDestinationPolicy().getEntryFor(destination);
                if (entry != null) {
                    entry.configure(broker, usageManager, answer);
                }
            }
            answer.init();
            return answer;
        } catch (Exception e) {
            LOG.error("Failed to create TopicSubscription ", e);
            JMSException jmsEx = new JMSException("Couldn't create TopicSubscription");
            jmsEx.setLinkedException(e);
            throw jmsEx;
        }
    }

    /**
     */
    private boolean hasDurableSubChanged(ConsumerInfo info1, ConsumerInfo info2) {
        if (info1.getSelector() != null ^ info2.getSelector() != null) {
            return true;
        }
        if (info1.getSelector() != null && !info1.getSelector().equals(info2.getSelector())) {
            return true;
        }
        return !info1.getDestination().equals(info2.getDestination());
    }

    @Override
    protected Set<ActiveMQDestination> getInactiveDestinations() {
        Set<ActiveMQDestination> inactiveDestinations = super.getInactiveDestinations();
        for (Iterator<ActiveMQDestination> iter = inactiveDestinations.iterator(); iter.hasNext();) {
            ActiveMQDestination dest = iter.next();
            if (!dest.isTopic()) {
                iter.remove();
            }
        }
        return inactiveDestinations;
    }

    public boolean isKeepDurableSubsActive() {
        return keepDurableSubsActive;
    }

    public void setKeepDurableSubsActive(boolean keepDurableSubsActive) {
        this.keepDurableSubsActive = keepDurableSubsActive;
    }

    public boolean durableSubscriptionExists(SubscriptionKey key) {
        return this.durableSubscriptions.containsKey(key);
    }

}