Third-party jar (Twitter4J) in Minecraft Server with Bukkit

Question

I have seen many errors with Twitter4j with Android, but I am not using it for Android. I am using it for Bukkit (Minecraft Plugin). For some reason, when I add twitter4j-core-3.0.3.jar to my project, I get a error when loading in the server console:

[SEVERE] Could not load 'plugins\Test.jar' in folder 'plugins'

org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: twitter4j/TwitterException
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:184)
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)
        at org.bukkit.craftbukkit.v1_6_R2.CraftServer.loadPlugins(CraftServer.java:239)
        at org.bukkit.craftbukkit.v1_6_R2.CraftServer.<init>(CraftServer.java:217)
        at net.minecraft.server.v1_6_R2.PlayerList.<init>(PlayerList.java:56)
        at net.minecraft.server.v1_6_R2.DedicatedPlayerList.<init>(SourceFile:11)
        at net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:106)
        at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:391)
        at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.NoClassDefFoundError: twitter4j/TwitterException
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:173)
        ... 9 more
Caused by: java.lang.ClassNotFoundException: twitter4j.TwitterException
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:80)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 12 more`

Since I am new to Java, I am really not getting what I am doing wrong here. This is my code (I do not think this is the issue, since the plugin fails to load ... :

                String TWITTER_CONSUMER_KEY = "XXXXXXXX";
            String TWITTER_SECRET_KEY = "XXXXXX";
            String TWITTER_ACCESS_TOKEN = "XXXXXXXXXX";
            String TWITTER_ACCESS_TOKEN_SECRET = "XXXXXX";

            ConfigurationBuilder cb = new ConfigurationBuilder();
            cb.setDebugEnabled(true).setOAuthConsumerKey(TWITTER_CONSUMER_KEY).setOAuthConsumerSecret(TWITTER_SECRET_KEY).setOAuthAccessToken(TWITTER_ACCESS_TOKEN).setOAuthAccessTokenSecret(TWITTER_ACCESS_TOKEN_SECRET);
            TwitterFactory tf = new TwitterFactory(cb.build());
            Twitter twitter = tf.getInstance();
            try {
                Query query = new Query(Username);
                QueryResult result;
                do {
                    result = twitter.search(query);
                    List<Status> tweets = result.getTweets();
                    for (Status tweet : tweets) 
                    {
                        String rawJSON = DataObjectFactory.getRawJSON(tweet);
                        try
                        {
                            BufferedWriter out = new BufferedWriter(new FileWriter((getDataFolder() + File.separator + "TwitterData.txt")));
                            out.write(rawJSON);
                            out.close();
                        }
                        catch (IOException ioe) 
                        {
                            ioe.printStackTrace();
                            System.out.println("Failed to store tweets: " + ioe.getMessage());          
                        }

                    }
                } 
                while ((query = result.nextQuery()) != null);
                System.exit(0);
            } 
            catch (TwitterException te)
            {
                te.printStackTrace();
                System.out.println("Failed to search tweets: " + te.getMessage());
                System.exit(-1);
            }

Why is Twitter4j not loading properly? Thanks!

EDIT: Also, the twitter4j-core-3.03.jar is in another directory on my computer. Is that a issue?

Answer 1

All jars needed by your Java program need to be on the classpath on the server. This includes Twitter4J in your case.