com.utad.flume.source.TwitterSource.java Source code

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Here is the source code for com.utad.flume.source.TwitterSource.java

Source

package com.utad.flume.source;

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.
 */

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.EventDrivenSource;
import org.apache.flume.channel.ChannelProcessor;
import org.apache.flume.conf.Configurable;
import org.apache.flume.event.EventBuilder;
import org.apache.flume.source.AbstractSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import twitter4j.FilterQuery;
import twitter4j.StallWarning;
import twitter4j.Status;
import twitter4j.StatusDeletionNotice;
import twitter4j.StatusListener;
import twitter4j.TwitterStream;
import twitter4j.TwitterStreamFactory;
import twitter4j.auth.AccessToken;
import twitter4j.conf.ConfigurationBuilder;
import twitter4j.json.DataObjectFactory;

/**
 * A Flume Source, which pulls data from Twitter's streaming API. Currently,
 * this only supports pulling from the sample API, and only gets new status
 * updates.
 */
public class TwitterSource extends AbstractSource implements EventDrivenSource, Configurable {

    private static final Logger logger = LoggerFactory.getLogger(TwitterSource.class);

    /** Information necessary for accessing the Twitter API */
    private String consumerKey;
    private String consumerSecret;
    private String accessToken;
    private String accessTokenSecret;

    private String[] keywords;

    /** The actual Twitter stream. It's set up to collect raw JSON data */
    private TwitterStream twitterStream;

    /**
     * The initialization method for the Source. The context contains all the
     * Flume configuration info, and can be used to retrieve any configuration
     * values necessary to set up the Source.
     */
    @Override
    public void configure(Context context) {
        consumerKey = context.getString(TwitterSourceConstants.CONSUMER_KEY_KEY);
        consumerSecret = context.getString(TwitterSourceConstants.CONSUMER_SECRET_KEY);
        accessToken = context.getString(TwitterSourceConstants.ACCESS_TOKEN_KEY);
        accessTokenSecret = context.getString(TwitterSourceConstants.ACCESS_TOKEN_SECRET_KEY);

        String keywordString = context.getString(TwitterSourceConstants.KEYWORDS_KEY, "");
        keywords = keywordString.split(",");
        for (int i = 0; i < keywords.length; i++) {
            keywords[i] = keywords[i].trim();
        }

        ConfigurationBuilder cb = new ConfigurationBuilder();
        cb.setOAuthConsumerKey(consumerKey);
        cb.setOAuthConsumerSecret(consumerSecret);
        cb.setOAuthAccessToken(accessToken);
        cb.setOAuthAccessTokenSecret(accessTokenSecret);
        cb.setJSONStoreEnabled(true);
        cb.setIncludeEntitiesEnabled(true);

        twitterStream = new TwitterStreamFactory(cb.build()).getInstance();
    }

    /**
     * Start processing events. This uses the Twitter Streaming API to sample
     * Twitter, and process tweets.
     */
    @Override
    public void start() {
        // The channel is the piece of Flume that sits between the Source and Sink,
        // and is used to process events.
        final ChannelProcessor channel = getChannelProcessor();

        final Map<String, String> headers = new HashMap<String, String>();

        // The StatusListener is a twitter4j API, which can be added to a Twitter
        // stream, and will execute methods every time a message comes in through
        // the stream.
        StatusListener listener = new StatusListener() {
            // The onStatus method is executed every time a new tweet comes in.
            public void onStatus(Status status) {
                // The EventBuilder is used to build an event using the headers and
                // the raw JSON of a tweet
                logger.debug(status.getUser().getScreenName() + ": " + status.getText());

                headers.put("timestamp", String.valueOf(status.getCreatedAt().getTime()));
                Event event = EventBuilder.withBody(DataObjectFactory.getRawJSON(status).getBytes(), headers);
                List<Event> events = Arrays.asList(event);
                channel.processEventBatch(events);
            }

            // This listener will ignore everything except for new tweets
            public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) {
            }

            public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
            }

            public void onScrubGeo(long userId, long upToStatusId) {
            }

            public void onException(Exception ex) {
            }

            public void onStallWarning(StallWarning warning) {
            }
        };

        logger.debug("Setting up Twitter sample stream using consumer key {} and" + " access token {}",
                new String[] { consumerKey, accessToken });
        // Set up the stream's listener (defined above),
        twitterStream.addListener(listener);

        // Set up a filter to pull out industry-relevant tweets
        if (keywords.length == 0) {
            logger.debug("Starting up Twitter sampling...");
            twitterStream.sample();
        } else {
            logger.debug("Starting up Twitter filtering...");

            FilterQuery query = new FilterQuery().track(keywords);
            twitterStream.filter(query);
        }
        super.start();
    }

    /**
     * Stops the Source's event processing and shuts down the Twitter stream.
     */
    @Override
    public void stop() {
        logger.debug("Shutting down Twitter sample stream...");
        twitterStream.shutdown();
        super.stop();
    }
}