com.freedomotic.bus.DestinationRegistry Maven / Gradle / Ivy

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/**
 *
 * Copyright (c) 2009-2014 Freedomotic team http://freedomotic.com
 *
 * This file is part of Freedomotic
 *
 * This Program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2, or (at your option) any later version.
 *
 * This Program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * Freedomotic; see the file COPYING. If not, see
 * .
 */
package com.freedomotic.bus;

import com.freedomotic.util.UidGenerator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Session;

/**
 * Destination registry. Caches destination registration.
 *
 * Future uses are:
 * 
 * - sanity check of bus operations
 * 

 * - improved log monitor facility based on contexts
 * 
 *
 * @author Freedomotic Team
 *
 */
// TODO LCG Should it be life cycle managed?
class DestinationRegistry {

    private final BusService busService;
    private Map consumer = new ConcurrentHashMap();

    /**
     *
     */
    DestinationRegistry(BusService busService) {
        super();
        this.busService = busService;

    }

    private synchronized BusDestination register(CreateDestinationAction command)
            throws JMSException {

        BusDestination destination;
        if (!consumer.containsKey(command.getQueueName())) {

            destination = command.create();
            consumer.put(command.getQueueName(), destination);

        } else {

            destination = consumer.get(command.getQueueName());
        }

        return destination;
    }

    /**
     *
     * @param queueName
     * @return
     * @throws JMSException
     */
    protected BusDestination registerCommandQueue(String queueName)
            throws JMSException {

        return registerQueue(queueName);
    }

    /**
     *
     * @param queueName
     * @return
     * @throws JMSException
     */
    protected BusDestination registerEventQueue(String queueName)
            throws JMSException {

        final String eventQueueName = "Consumer."
                + UidGenerator.getNextStringUid() + ".VirtualTopic."
                + queueName;

        return registerQueue(eventQueueName);
    }

    private BusDestination registerQueue(String queueName) throws JMSException {

        CreateDestinationAction command = new DestinationAction(queueName) {

            @Override
            public BusDestination create() throws JMSException {

                final Session receiveSession = busService.getReceiveSession();

                Destination destination = receiveSession
                        .createQueue(getQueueName());

                BusDestination busDestination = new BusDestination(destination,
                        getQueueName(), DestinationType.QUEUE);

                return busDestination;
            }
        };

        return register(command);
    }

    /**
     *
     * @param queueName
     * @return
     * @throws JMSException
     */
    public BusDestination registerTopic(String queueName) throws JMSException {

        CreateDestinationAction command = new DestinationAction(queueName) {

            @Override
            public BusDestination create() throws JMSException {

                final Session sendSession = busService.getSendSession();

                Destination destination = sendSession
                        .createTopic("VirtualTopic." + getQueueName());

                BusDestination busDestination = new BusDestination(destination,
                        getQueueName(), DestinationType.TOPIC);

                return busDestination;

            }
        };

        return register(command);
    }

    private interface CreateDestinationAction {

        public BusDestination create() throws JMSException;

        public String getQueueName();
    }

    private abstract class DestinationAction implements CreateDestinationAction {

        private String queueName;

        public DestinationAction(String queueName) {

            this.queueName = queueName;
        }

        @Override
        public abstract BusDestination create() throws JMSException;

        @Override
        public String getQueueName() {

            return queueName;
        }

    }
}