无法连接到Twitter服务（Android）

Question

所以，我现在正在学习Android，我需要帮助。我无法测试我的服务，因为连接API Twitter有错误。在这个项目中，我正在使用jtwitter.jar库。但是，LogCat捕获异常：

> 02-12 22:10:09.880 4533-4547/com.marakana.yamba W/dalvikvm: threadid=11: thread exiting with uncaught exception (group=0x41af0da0)
02-12 22:10:09.881 4533-4547/com.marakana.yamba E/AndroidRuntime: FATAL EXCEPTION: UpdaterService-Updater
02-12 22:10:09.881 4533-4547/com.marakana.yamba E/AndroidRuntime: Process: com.marakana.yamba, PID: 4533
02-12 22:10:09.881 4533-4547/com.marakana.yamba E/AndroidRuntime: java.lang.NullPointerException
02-12 22:10:09.881 4533-4547/com.marakana.yamba E/AndroidRuntime:     at com.marakana.yamba.UpdaterService$Updater.run(UpdaterService.java:86)
02-12 22:10:07.737 4533-4533/com.marakana.yamba I/YambaApplication: onCreated
02-12 22:10:07.738 4533-4533/com.marakana.yamba D/UpdaterService: onCreated
02-12 22:10:07.739 4533-4533/com.marakana.yamba D/UpdaterService: onStarted
02-12 22:10:07.740 4533-4547/com.marakana.yamba D/UpdaterService: Updater running
02-12 22:10:09.880 4533-4547/com.marakana.yamba E/UpdaterService: Failed to connect to twitter service

我不知道为什么服务不起作用。我有jtwitter-yamba.jar作为库。但是，在LogCat中，错误在上（Twitter.Status状态：时间轴）。这是我的代码之一：

UpdaterService.java

    package com.marakana.yamba;

`import android.app.Service;`
`import android.content.Intent;`
`import android.os.IBinder;`
`import android.support.annotation.Nullable;`
`import android.util.Log;`
`import java.util.List;`
`import winterwell.jtwitter.Twitter;`
`import winterwell.jtwitter.TwitterException;`

public class UpdaterService extends Service {
    static final String TAG = "UpdaterService";

    static final int DELAY = 6000;//a minute
    private boolean runFlag = false;
    private Updater updater;
    private YambaApplication yamba;

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate(){
        super.onCreate();
        this.yamba = (YambaApplication) getApplication();
        this.updater = new Updater();

        Log.d(TAG, "onCreated");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId){
        super.onStartCommand(intent, flags, startId);

        this.runFlag = true;
        this.updater.start();
        this.yamba.setServiceRunning(true);

        Log.d(TAG, "onStarted");
        return START_STICKY;
    }

    @Override
    public void onDestroy(){
        super.onDestroy();

        this.runFlag= false;
        this.updater.interrupt();
        this.updater = null;
        this.yamba.setServiceRunning(false);

        Log.d(TAG, "onDestroyed");
    }

    /**
     * Thread that performs the actual update from the online service
     */
    private class Updater extends Thread{
        List<Twitter.Status> timeline;

        public Updater(){
            super("UpdaterService-Updater");
        }

        @Override
        public void run(){
            UpdaterService updaterService = UpdaterService.this;
            while(updaterService.runFlag){
                Log.d(TAG, "Updater running");
                try {
                    //Some work goes here...
                    //Get the timeline from the cloud
                    try{
                        timeline = yamba.getTwitter().getFriendsTimeline();
                    }catch (TwitterException e){
                        Log.e(TAG, "Failed to connect to twitter service", e);
                    }
                    //Loop over the timeline and print it out
                    for (Twitter.Status status : timeline){
                        Log.d(TAG, String.format("%s: %s,", status.user.name, status.text));
                    }

                    Log.d(TAG, "Updater ran");
                    Thread.sleep(DELAY);
                }catch (InterruptedException e){
                    updaterService.runFlag = false;
                }
            }
        }
    }//Updater
}