org.wso2.cep.uima.demo.StatusHandler.java Source code

Introduction

Here is the source code for org.wso2.cep.uima.demo.StatusHandler.java

Source

/*
 *
 * Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. 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.wso2.cep.uima.demo;

import org.apache.activemq.ActiveMQConnectionFactory;
import twitter4j.*;

import javax.jms.*;

/***
 *  Listener implementation for the Twitter Streamer
 */
public class StatusHandler implements StatusListener {

    private MessageProducer producer;
    private Session session;
    private static Logger logger = Logger.getLogger(StatusHandler.class);

    /***
     *
     * @param JMSUrl String | URL of the JMS Broker to send the messages to
     */
    public StatusHandler(String JMSUrl, String topicName) throws JMSException {
        // create the factory for ActiveMQ connection
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(JMSUrl);
        Connection connection = factory.createConnection();
        connection.start();
        logger.info("ActiveMQ connection established for StatusHandler successfully");

        // Create a non-transactional session with automatic acknowledgement
        session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

        // Create a reference to the queue test_queue in this session.
        Topic topic = session.createTopic(topicName);

        // Create a producer for queue
        producer = session.createProducer(topic);
        logger.info("ActiveMQ producer successfully created for TwitterStreamer");
    }

    /***
     * Method to handle arrival of a status to the stream
     * @param status Recieved Tweet as a Status Object
     */
    @Override
    public void onStatus(Status status) {
        Logger.getLogger(StatusHandler.class).info("Tweet Recieved : " + status.getText());
        if (producer == null) {
            throw new NullPointerException("ActiveMQ producer not set for StatusHandler");
        }

        // send the tweet to the queue
        try {
            TextMessage tweetMessage = session.createTextMessage(status.getText());
            producer.send(tweetMessage);
        } catch (JMSException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void onException(Exception arg0) {
        Logger.getLogger(StatusHandler.class)
                .error("Exception occured while streaming for tweets : " + arg0.getMessage());
        arg0.printStackTrace();
    }

    @Override
    public void onDeletionNotice(StatusDeletionNotice arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onScrubGeo(long arg0, long arg1) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onStallWarning(StallWarning arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onTrackLimitationNotice(int arg0) {
        Logger.getLogger(StatusHandler.class).error("Track Limitations Exceeded");

    }

}