org.dawnsci.commandserver.core.util.JSONUtils.java Source code

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Here is the source code for org.dawnsci.commandserver.core.util.JSONUtils.java

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/*
 * Copyright (c) 2012 Diamond Light Source Ltd.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.dawnsci.commandserver.core.util;

import java.net.URI;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.DeliveryMode;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;

import org.dawnsci.commandserver.core.ConnectionFactoryFacade;

import com.fasterxml.jackson.databind.ObjectMapper;

public class JSONUtils {

    public static final void sendTopic(Object message, String topicName, URI uri) throws Exception {

        Connection connection = null;
        try {
            ConnectionFactory connectionFactory = ConnectionFactoryFacade.createConnectionFactory(uri);
            connection = connectionFactory.createConnection();
            connection.start();

            sendTopic(connection, message, topicName, uri);

        } finally {
            if (connection != null)
                connection.close();
        }
    }

    /**
     * Generic way of sending a topic notification
     * @param connection - does not get closed afterwards nust be started before.
     * @param message
     * @param topicName
     * @param uri
     * @throws Exception
     */
    private static final void sendTopic(Connection connection, Object message, String topicName, URI uri)
            throws Exception {

        // JMS messages are sent and received using a Session. We will
        // create here a non-transactional session object. If you want
        // to use transactions you should set the first parameter to 'true'
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

        try {
            Topic topic = session.createTopic(topicName);

            MessageProducer producer = session.createProducer(topic);

            final ObjectMapper mapper = new ObjectMapper();

            // Here we are sending the message out to the topic
            TextMessage temp = session.createTextMessage(mapper.writeValueAsString(message));
            producer.send(temp, DeliveryMode.NON_PERSISTENT, 1, 5000);

        } finally {
            session.close();
        }
    }

}