Java tutorial
/* * Copyright 2009 Laurent Bovet, Swiss Post IT * * Licensed 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 hermes.ext.imq; import hermes.Domain; import hermes.Hermes; import hermes.HermesAdmin; import hermes.browser.HermesBrowser; import hermes.config.DestinationConfig; import hermes.ext.HermesAdminSupport; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.Comparator; import java.util.Enumeration; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.jms.Connection; import javax.jms.ConnectionFactory; import javax.jms.JMSException; import javax.jms.MapMessage; import javax.jms.Message; import javax.jms.MessageConsumer; import javax.jms.MessageListener; import javax.jms.Session; import javax.jms.Topic; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Support for Sun MQ (aka Java MQ or even Open MQ, technically named imq). * * @author bovetl * @version $Revision$ * @since 01.00.00.00 */ public class ImqAdmin extends HermesAdminSupport implements HermesAdmin, MessageListener { static final String DEST_LIST_TOPIC_NAME = "mq.metrics.destination_list"; static final String QUEUE_METRICS_TOPIC_PREFIX = "mq.metrics.destination.queue."; static final String TOPIC_METRICS_TOPIC_PREFIX = "mq.metrics.destination.topic."; private final ConnectionFactory connectionFactory; private Connection connection; private Session session; private MessageConsumer destListTopicSubscriber; private final Map<String, MessageConsumer> destMetricTopicSubscribers = new HashMap<String, MessageConsumer>(); private final Map<String, Long> messageCounts = new HashMap<String, Long>(); private final Map<String, Map<String, Long>> stats = new HashMap<String, Map<String, Long>>(); private List<DestinationConfig> destinations = new ArrayList<DestinationConfig>(); private static Log LOG = LogFactory.getLog(ImqAdminFactory.class); private final Object destListGuard = new Object(); private final Object destMetricGuard = new Object(); public ImqAdmin(Hermes hermes, ConnectionFactory connectionFactory) { super(hermes); this.connectionFactory = connectionFactory; LOG.debug("Building ImqAdmin"); try { connection = this.connectionFactory.createConnection(); connection.start(); session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); Topic destListTopic = session.createTopic(DEST_LIST_TOPIC_NAME); destListTopicSubscriber = session.createConsumer(destListTopic); destListTopicSubscriber.setMessageListener(this); } catch (JMSException e) { throw new RuntimeException(e); } } @Override public Collection<DestinationConfig> discoverDestinationConfigs() throws JMSException { LOG.debug("Discovering destination(s)"); try { synchronized (destListGuard) { destListGuard.wait(); } } catch (InterruptedException e) { } LOG.debug("Discovered " + destinations.size() + " destination(s)"); return destinations; } @Override public int getDepth(DestinationConfig destinationConfig) throws JMSException { LOG.debug("Getting depth"); try { subscribeToDestMetricTopic(destinationConfig.getShortName(), destinationConfig.getDomain()); synchronized (destMetricGuard) { destMetricGuard.wait(5000); } } catch (InterruptedException e) { } Long result = messageCounts.get(destinationConfig.getShortName()); LOG.debug("Got depth for " + destinationConfig.getShortName() + ": " + result); if (result == null) { throw new RuntimeException("Timeout: Got no data from metric topic."); } clearDestMetricTopicSubscribers(); return result.intValue(); } @Override public Map<String, Long> getStatistics(DestinationConfig destination) throws JMSException { LOG.debug("Getting statistics for " + destination); try { synchronized (destMetricGuard) { subscribeToDestMetricTopic(destination.getShortName(), destination.getDomain()); destMetricGuard.wait(5000); } } catch (InterruptedException e) { } Map<String, Long> result = stats.get(destination.getShortName()); clearDestMetricTopicSubscribers(); if (result == null) { throw new RuntimeException("Timeout: Got no data from metric topic."); } return result; } @Override public void close() throws JMSException { LOG.debug("Closing IMQ Session"); clearDestMetricTopicSubscribers(); destListTopicSubscriber.close(); session.close(); connection.close(); } @Override public void onMessage(Message msg) { try { MapMessage mapMsg = (MapMessage) msg; String type = mapMsg.getStringProperty("type"); LOG.debug("Got admin message from broker of type: " + type); if (type.equals(DEST_LIST_TOPIC_NAME)) { List<DestinationConfig> result = new ArrayList<DestinationConfig>(); for (@SuppressWarnings("unchecked") Enumeration e = mapMsg.getMapNames(); e.hasMoreElements();) { String name = (String) e.nextElement(); @SuppressWarnings("unchecked") Map<String, String> object = (Map<String, String>) mapMsg.getObject(name); DestinationConfig dest = HermesBrowser.getConfigDAO().createDestinationConfig(); dest.setName(object.get("name")); dest.setShortName(object.get("name")); dest.setDomain("queue".equals(object.get("type")) ? Domain.QUEUE.getId() : ("topic".equals(object.get("type")) ? Domain.TOPIC.getId() : Domain.UNKNOWN.getId())); result.add(dest); } Collections.sort(result, new Comparator<DestinationConfig>() { @Override public int compare(DestinationConfig o1, DestinationConfig o2) { return o1.getShortName().compareTo(o2.getShortName()); } }); destinations = result; synchronized (destListGuard) { destListGuard.notifyAll(); } } else if (type.startsWith(QUEUE_METRICS_TOPIC_PREFIX)) { LOG.debug("Got queue metrics: " + type); String queueName = type.substring(QUEUE_METRICS_TOPIC_PREFIX.length()); messageCounts.put(queueName, mapMsg.getLong("numMsgs")); HashMap<String, Long> map = new HashMap<String, Long>(); @SuppressWarnings("unchecked") Enumeration<String> e = mapMsg.getMapNames(); while (e.hasMoreElements()) { String name = e.nextElement(); map.put(name, mapMsg.getLong(name)); } stats.put(queueName, map); LOG.debug("Stored stats for: " + queueName); synchronized (destMetricGuard) { destMetricGuard.notifyAll(); } } else if (type.startsWith(TOPIC_METRICS_TOPIC_PREFIX)) { LOG.debug("Got topic metrics: " + type); String topicName = type.substring(TOPIC_METRICS_TOPIC_PREFIX.length()); messageCounts.put(topicName, mapMsg.getLong("numMsgs")); HashMap<String, Long> map = new HashMap<String, Long>(); @SuppressWarnings("unchecked") Enumeration<String> e = mapMsg.getMapNames(); while (e.hasMoreElements()) { String name = e.nextElement(); map.put(name, mapMsg.getLong(name)); } stats.put(topicName, map); LOG.debug("Stored stats for: " + topicName); synchronized (destMetricGuard) { destMetricGuard.notifyAll(); } } } catch (JMSException e) { throw new RuntimeException(e); } } private MessageConsumer subscribeToDestMetricTopic(String destName, int domain) throws JMSException { LOG.debug("Subscribing to " + destName); String topicName = null; if (domain == Domain.QUEUE.getId()) { topicName = QUEUE_METRICS_TOPIC_PREFIX + destName; } else if (domain == Domain.TOPIC.getId()) { topicName = TOPIC_METRICS_TOPIC_PREFIX + destName; } Topic destListTopic = session.createTopic(topicName); MessageConsumer subscriber = session.createConsumer(destListTopic); subscriber.setMessageListener(this); LOG.debug("Created subscriber " + subscriber + " listening to " + topicName); return subscriber; } private void clearDestMetricTopicSubscribers() throws JMSException { for (MessageConsumer subscriber : destMetricTopicSubscribers.values()) { LOG.debug("Closing subscriber: " + subscriber); subscriber.close(); } destMetricTopicSubscribers.clear(); } }