au.edu.anu.portal.portlets.tweetal.logic.TwitterLogic.java Source code

Introduction

Here is the source code for au.edu.anu.portal.portlets.tweetal.logic.TwitterLogic.java

Source

/**
 * Copyright 2009-2011 The Australian National University
 *
 *    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 au.edu.anu.portal.portlets.tweetal.logic;

import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import twitter4j.http.AccessToken;
import twitter4j.http.RequestToken;

public class TwitterLogic {

    private String consumerKey;
    private String consumerSecret;

    private final Log log = LogFactory.getLog(getClass().getName());

    /** cache for authenticated users' twitter object */
    private Cache twitterCache;

    /** Twitter OAuth authorized consumer instance */
    private Twitter twitterConsumer;

    /**
     * no arg constructor
     */
    public TwitterLogic() {
        // create cache, singleton
        CacheManager.create();
        twitterCache = CacheManager.getInstance().getCache("au.edu.anu.portal.portlets.tweetal.TweetalCache");
    }

    /**
     * Authenticate User to Twitter
     * @param userToken
     * @param userSecret
     * @return OAuth authenticated instance of Twitter object
     */
    public Twitter getTwitterAuthForUser(String userToken, String userSecret) {
        if (StringUtils.isBlank(userToken) || StringUtils.isBlank(userSecret)) {
            return null;
        }

        String cacheKey = userToken + "|" + userSecret;
        //String cacheKey = userToken;

        Element element = twitterCache.get(cacheKey);

        // caching authenticated oauth objects
        if (element == null) {
            synchronized (twitterCache) {
                // if it is still null after acquiring lock
                element = twitterCache.get(cacheKey);

                if (element == null) {
                    // log.debug("cache miss: getting authorized instance for " + userToken);
                    Twitter twitter = new TwitterFactory().getOAuthAuthorizedInstance(consumerKey, consumerSecret,
                            new AccessToken(userToken, userSecret));

                    element = new Element(cacheKey, twitter);
                    twitterCache.put(element);
                }
            }
            // } else {
            //     log.debug("cache hit: getting authorized instance for " + userToken);
        }

        return (Twitter) element.getObjectValue();
    }

    /**
     * Get the screen name of the Twitter user (eg KRuddPM)
     * @param userToken
     * @param userSecret
     * @return the screen name, or null
     */
    public String getScreenName(String userToken, String userSecret) {
        Twitter twitter = getTwitterAuthForUser(userToken, userSecret);
        if (twitter == null) {
            return null;
        }

        try {
            return twitter.verifyCredentials().getScreenName();

        } catch (TwitterException e) {
            log.error("Error getting screen name: " + e.getClass() + ": " + e.getMessage());
        }
        return null;
    }

    /**
     * Get a RequestToken for this Twitter application. This token MUST be captured so that it can 
     * be used for future requests in the same process.
     * @return RequestToken or null if error
     */
    public RequestToken getRequestToken() {
        if (twitterConsumer == null) {
            log.error("No OAuth instance");
            return null;
        }

        try {
            return twitterConsumer.getOAuthRequestToken();

        } catch (TwitterException e) {
            log.error("Error getting RequestToken: " + e.getClass() + ": " + e.getMessage());
        }

        return null;
    }

    /**
     * Get an AccessToken for the given RequestToken and user entered pin.
     * @param requestToken
     * @param pin
     * @return AccessToken or null if error
     */
    public AccessToken getAccessToken(RequestToken requestToken, String pin) {
        if (twitterConsumer == null) {
            log.error("No OAuth instance");
            return null;
        }

        try {
            return twitterConsumer.getOAuthAccessToken(requestToken, pin);

        } catch (TwitterException e) {
            log.error("Error getting AccessToken: " + e.getClass() + ": " + e.getMessage());
        }

        return null;
    }

    /**
     * Set consumer key and secret, and get OAuth authorized instance
     */
    public void setOAuthConsumer(String consumerKey, String consumerSecret) {
        this.consumerKey = consumerKey;
        this.consumerSecret = consumerSecret;

        if (StringUtils.isEmpty(consumerKey) || StringUtils.isEmpty(consumerSecret)) {
            // no key in session, no access
            log.error("Empty consumer secret and key");
            twitterConsumer = null;
            return;
        }

        twitterConsumer = new TwitterFactory().getOAuthAuthorizedInstance(consumerKey, consumerSecret);
    }

    /**
     * Validate that twitter consumer is not null (i.e. key and secret are not null)
     * @return false if error
     */
    public boolean validate() {
        if (twitterConsumer == null) {
            log.error("No OAuth instance");
            return false;
        }

        try {
            // TODO: it seems that this method does not verify consumer key and secret (Denny)
            return twitterConsumer.test();
        } catch (TwitterException e) {
            log.error("Error in testing API: " + e.getClass() + ": " + e.getMessage());
        }

        return false;
    }

    public boolean verifyCredentials(String userToken, String userSecret) {
        Twitter twitter = getTwitterAuthForUser(userToken, userSecret);

        try {
            twitter.verifyCredentials();
            return true;

        } catch (TwitterException e) {
            log.error("Error: Credentials are invalid.\n" + e.getClass() + ":\n" + e.getMessage());
        }
        return false;
    }

}