com.wso2.stream.connector.protocol.TwitterPollingConsumer.java Source code

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Here is the source code for com.wso2.stream.connector.protocol.TwitterPollingConsumer.java

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/*
 * Copyright (c) 2014, 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 com.wso2.stream.connector.protocol;

import java.util.LinkedList;
import java.util.Properties;
import java.util.Queue;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.wso2.stream.connector.protocol.TweetContent;
import com.wso2.stream.connector.protocol.TwitterConstant;
import com.wso2.stream.connector.protocol.TwitterInjectHandler;

import twitter4j.FilterQuery;
import twitter4j.StallWarning;
import twitter4j.Status;
import twitter4j.StatusDeletionNotice;
import twitter4j.StatusListener;
import twitter4j.TwitterStream;
import twitter4j.TwitterStreamFactory;
import twitter4j.conf.ConfigurationBuilder;

public class TwitterPollingConsumer {

    private static final Log logger = LogFactory.getLog(TwitterPollingConsumer.class.getName());

    // twitter auth
    private String consumerKey;
    private String consumerSecret;
    private String accessToken;
    private String accessSecret;

    private Queue<Status> twitterQueue;

    private TwitterInjectHandler injectHandler;
    private String[] filterTags;

    private OMFactory omFactory;
    private TweetContent tweetContent;

    /**
     * TwitterPollingConsumer constructor
     * This is call when initializing the polling processor
     * @param twitterProperties
     */
    public TwitterPollingConsumer(Properties twitterProperties) {
        loadCredentials(twitterProperties);
        String tags = twitterProperties.getProperty(TwitterConstant.FILTER_TAG);

        this.filterTags = tags.split(";");

        twitterQueue = new LinkedList<Status>();
        omFactory = OMAbstractFactory.getOMFactory();
        tweetContent = new TweetContent();

        //Establishing connection with twitter streaming api
        setupConnection();
        logger.info("Twitter connection setup successfully.");
    }

    /**
     * Load credentials from the Twitter end-point property file.
     * @param properties
     */
    private void loadCredentials(Properties properties) {
        this.consumerKey = properties.getProperty(TwitterConstant.CONSUMER_KEY);
        this.consumerSecret = properties.getProperty(TwitterConstant.CONSUMER_SECRET);
        this.accessSecret = properties.getProperty(TwitterConstant.ACCESS_SECRET);
        this.accessToken = properties.getProperty(TwitterConstant.ACCESS_TOKEN);
    }

    public void registerHandler(TwitterInjectHandler twitterInjectHandler) {
        this.injectHandler = twitterInjectHandler;
    }

    /**
     * Setting up a connection with Twitter Stream API with the given credentials
     */
    private void setupConnection() {
        StatusListener listener = new StatusListenerImpl();

        ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
        configurationBuilder.setDebugEnabled(true).setOAuthConsumerKey(consumerKey)
                .setOAuthConsumerSecret(consumerSecret).setOAuthAccessToken(accessToken)
                .setOAuthAccessTokenSecret(accessSecret);

        TwitterStream twitterStream = new TwitterStreamFactory(configurationBuilder.build()).getInstance();
        twitterStream.addListener(listener);

        FilterQuery query = new FilterQuery();
        query.language(new String[] { "en" });
        query.track(filterTags);
        twitterStream.filter(query);
    }

    public void run() {
        poll();
    }

    public void execute() {
        poll();
    }

    /**
     * This is invoked each time when Inbound-endpoint triggers
     * @return
     */
    public Object poll() {
        try {
            while (twitterQueue.size() > 0) {
                Status status = twitterQueue.poll();
                OMElement bodyContent = tweetContent.createBodyContent(omFactory, status);
                injectHandler.invoke(bodyContent);
            }

        } catch (Exception e) {
            logger.error("Error while receiving Twitter message. " + e.getMessage(), e);
        }
        return null;
    }

    /**
     * Twitter Stream Listener Impl
     * onStatus will invoke whenever new twitter come. 
     * New Twitter is store in queue until it is inbound-endpoint poll
     *
     */
    class StatusListenerImpl implements StatusListener {
        public void onStatus(Status status) {
            if (status.getRetweetedStatus() == null) {
                twitterQueue.add(status);
            }
        }

        public void onException(Exception ex) {
            logger.error("Twitter source threw an exception", ex);
        }

        public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) {
            logger.debug("Got a status deletion notice id:" + statusDeletionNotice.getStatusId());
        }

        public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
            logger.debug("Got track limitation notice: " + numberOfLimitedStatuses);
        }

        public void onScrubGeo(long userId, long upToStatusId) {
            logger.debug("Got scrub_geo event userId:" + userId + " upToStatusId:" + upToStatusId);
        }

        public void onStallWarning(StallWarning warning) {
            logger.debug("Got stall warning:" + warning);
        }

    }

}