rtb.RandomTweetBot.java Source code

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Here is the source code for rtb.RandomTweetBot.java

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/*
 * Copyright 2014 Kohei Yamamoto
 *
 * Licensed 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 rtb;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

public class RandomTweetBot {
    private Twitter twitter;
    private List<Tweet> tweets;
    private Random random;
    private Tweet previousTweet;
    private boolean allowsReply;
    private Logger logger;

    public RandomTweetBot(final boolean reply) {
        twitter = TwitterFactory.getSingleton();
        tweets = new ArrayList<>();
        random = new Random(System.currentTimeMillis());
        previousTweet = null;
        allowsReply = reply;
        logger = LoggerFactory.getLogger(RandomTweetBot.class);
    }

    public Tweet getTweet(final int i) {
        return tweets.get(i);
    }

    public void setPrevTweet(Tweet tweet) {
        previousTweet = tweet;
    }

    /**
     * Read in JSON tweets file.
     * @param fileName tweets file in JSON form 
     * @return the number of tweets in the file
     * @throws JsonProcessingException
     * @throws IOException
     */
    public int readJsonFile(String fileName) throws JsonProcessingException, IOException {
        ObjectMapper mapper = new ObjectMapper();
        tweets = mapper.readValue(new File(fileName), new TypeReference<List<Tweet>>() {
        });
        return tweets.size();
    }

    /**
     * Get a tweet randomly from tweets list in this class. For avoiding duplicated error, use the tweet that is different from previous one.
     * @return tweet text
     */
    public Tweet nextTweet() {
        Tweet tweet = null;
        do {
            tweet = getTweet(random.nextInt(tweets.size()));
        } while (equalsPreviousTweet(tweet) || !allows(tweet));
        return tweet;
    }

    /* package */ boolean equalsPreviousTweet(Tweet tweet) {
        return previousTweet != null && previousTweet.equals(tweet);
    }

    /* package */ boolean allows(Tweet tweet) {
        return allowsReply || !tweet.isReply();
    }

    /**
     * Update twitter status with a random tweet from the list in this class. 
     * @return the updated tweet
     * @throws TwitterException
     */
    public String updateNextTweet() throws TwitterException {
        Tweet tweet = nextTweet();
        setPrevTweet(tweet);
        try {
            updateStatus(tweet);
            logger.info("Tweet \"{}\".", tweet);
            return tweet.getText();
        } catch (TwitterException e) {
            logger.info("Tweet failed.", e);
            return "";
        }
    }

    /* package */ String updateStatus(Tweet tweet) throws TwitterException {
        if (tweet == null)
            throw new IllegalArgumentException();
        return twitter.updateStatus(tweet.toString()).getText();
    }
}