org.apilytic.currency.service.impl.DefaultTwitterService.java Source code

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Here is the source code for org.apilytic.currency.service.impl.DefaultTwitterService.java

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/*
 * Copyright 2002-2013 the original author or authors
 *
 *     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 org.apilytic.currency.service.impl;

import java.util.Map;
import java.util.SortedSet;
import java.util.TreeSet;

import org.apilytic.currency.model.TwitterMessage;
import org.apilytic.currency.service.TwitterService;
import org.apilytic.currency.support.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.core.MessagingTemplate;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;
import org.springframework.social.twitter.api.Tweet;
import org.springframework.stereotype.Service;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

/**
 * Implementation of the {@link TwitterService} interface.
 *
 * @author Georgi Lambov
 * @since  1.0
 */
@Service
public class DefaultTwitterService implements TwitterService {

    /** Holds a collection of polled Twitter messages */
    private final Cache<Long, TwitterMessage> twitterMessages;

    @Autowired
    @Qualifier("controlBusChannel")
    private DirectChannel channel;

    /**
     * Constructor that initializes the 'twitterMessages' Map as a simple LRU
     * cache. @See http://blogs.oracle.com/swinger/entry/collections_trick_i_lru_cache
     */
    public DefaultTwitterService() {

        twitterMessages = CacheBuilder.newBuilder().maximumSize(10).build();

    }

    /** {@inheritDoc} */
    @Override
    public SortedSet<TwitterMessage> getTwitterMessages(Long tweetId, SortOrder sortOrder) {

        final TreeSet<TwitterMessage> tweets = new TreeSet<TwitterMessage>();

        if (tweetId != null) {

            final Map<Long, TwitterMessage> twitterMessagesAsMap = twitterMessages.asMap();

            for (Long id : twitterMessagesAsMap.keySet()) {
                if (id.compareTo(tweetId) > 0) {
                    tweets.add(twitterMessages.getIfPresent(id));
                }
            }

        } else {
            tweets.addAll(this.twitterMessages.asMap().values());
        }

        if (SortOrder.DESCENDING.equals(sortOrder)) {
            return tweets.descendingSet();
        }

        return tweets;
    }

    /** {@inheritDoc} */
    @Override
    public void startTwitterAdapter() {

        final MessagingTemplate m = new MessagingTemplate();
        final Message<String> operation = MessageBuilder.withPayload("@twitter.start()").build();

        m.send(channel, operation);

    }

    /** {@inheritDoc} */
    @Override
    public void stopTwitterAdapter() {

        final MessagingTemplate m = new MessagingTemplate();
        final Message<String> operation = MessageBuilder.withPayload("@twitter.stop()").build();

        m.send(channel, operation);

    }

    /** {@inheritDoc} */
    @Override
    public boolean isTwitterAdapterRunning() {

        final MessagingTemplate m = new MessagingTemplate();
        final Message<String> operation = MessageBuilder.withPayload("@twitter.isRunning()").build();

        @SuppressWarnings("unchecked")
        Message<Boolean> reply = (Message<Boolean>) m.sendAndReceive(channel, operation);

        return reply.getPayload();

    }

    /**
     * Called by Spring Integration to populate a simple LRU cache.
     *
     * @param tweet - The Spring Integration tweet object.
     */
    public void addTwitterMessages(Tweet tweet) {

        this.twitterMessages.put(tweet.getId(), new TwitterMessage(tweet.getId(), tweet.getCreatedAt(),
                tweet.getText(), tweet.getFromUser(), tweet.getProfileImageUrl()));

    }

}