org.taverna.server.master.notification.TwitterDispatcher.java Source code

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Here is the source code for org.taverna.server.master.notification.TwitterDispatcher.java

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/*
 * Copyright (C) 2011 The University of Manchester
 * 
 * See the file "LICENSE.txt" for license terms.
 */
package org.taverna.server.master.notification;

import static twitter4j.conf.PropertyConfiguration.OAUTH_ACCESS_TOKEN;
import static twitter4j.conf.PropertyConfiguration.OAUTH_ACCESS_TOKEN_SECRET;
import static twitter4j.conf.PropertyConfiguration.OAUTH_CONSUMER_KEY;
import static twitter4j.conf.PropertyConfiguration.OAUTH_CONSUMER_SECRET;

import java.util.Properties;

import twitter4j.Twitter;
import twitter4j.TwitterFactory;
import twitter4j.conf.Configuration;
import twitter4j.conf.PropertyConfiguration;
import twitter4j.auth.AuthorizationFactory;

/**
 * Super simple-minded twitter dispatcher. You need to tell it your consumer key
 * and secret as part of the connection parameters, for example via a dispatcher
 * URN of "<tt>twitter:fred:bloggs</tt>" where <tt>fred</tt> is the key and
 * <tt>bloggs</tt> is the secret.
 * 
 * @author Donal Fellows
 */
public class TwitterDispatcher extends RateLimitedDispatcher {
    public static final int MAX_MESSAGE_LENGTH = 140;
    public static final char ELLIPSIS = '\u2026';

    private String token = "";
    private String secret = "";

    public void setAccessToken(String token) {
        this.token = valid(token, "");
    }

    public void setAccessSecret(String secret) {
        this.secret = valid(secret, "");
    }

    private Properties getConfig() throws NotConfiguredException {
        if (token.isEmpty() || secret.isEmpty())
            throw new NotConfiguredException();
        Properties p = new Properties();
        p.setProperty(ACCESS_TOKEN_PROP, token);
        p.setProperty(ACCESS_SECRET_PROP, secret);
        return p;
    }

    public static final String ACCESS_TOKEN_PROP = OAUTH_ACCESS_TOKEN;
    public static final String ACCESS_SECRET_PROP = OAUTH_ACCESS_TOKEN_SECRET;

    private Twitter getTwitter(String key, String secret) throws Exception {
        if (key.isEmpty() || secret.isEmpty())
            throw new NoCredentialsException();

        Properties p = getConfig();
        p.setProperty(OAUTH_CONSUMER_KEY, key);
        p.setProperty(OAUTH_CONSUMER_SECRET, secret);

        Configuration config = new PropertyConfiguration(p);
        TwitterFactory factory = new TwitterFactory(config);
        Twitter t = factory.getInstance(AuthorizationFactory.getInstance(config));
        // Verify that we can connect!
        t.getOAuthAccessToken();
        return t;
    }

    // TODO: Get secret from credential manager
    @Override
    public void dispatch(String messageSubject, String messageContent, String targetParameter) throws Exception {
        // messageSubject ignored
        String[] target = targetParameter.split(":", 2);
        if (target == null || target.length != 2)
            throw new Exception("missing consumer key or secret");
        String who = target[0];
        if (!isSendAllowed(who))
            return;
        Twitter twitter = getTwitter(who, target[1]);

        if (messageContent.length() > MAX_MESSAGE_LENGTH)
            messageContent = messageContent.substring(0, MAX_MESSAGE_LENGTH - 1) + ELLIPSIS;
        twitter.updateStatus(messageContent);
    }

    @Override
    public boolean isAvailable() {
        try {
            // Try to create the configuration and push it through as far as
            // confirming that we can build an access object (even if it isn't
            // bound to a user)
            new TwitterFactory(new PropertyConfiguration(getConfig())).getInstance();
            return true;
        } catch (Exception e) {
            return false;
        }
    }

    /**
     * Indicates that the dispatcher has not been configured with service
     * credentials.
     * 
     * @author Donal Fellows
     */
    public static class NotConfiguredException extends Exception {
        NotConfiguredException() {
            super("not configured with xAuth key and secret; " + "dispatch not possible");
        }
    }

    /**
     * Indicates that the user did not supply their credentials.
     * 
     * @author Donal Fellows
     */
    public static class NoCredentialsException extends Exception {
        NoCredentialsException() {
            super("no consumer key and secret present; " + "dispatch not possible");
        }
    }
}