NullPointer和java.util.Timer $ TimerImpl.run

Question

我真的不明白这里发生了什么。我只是写一个Android应用程序来收集Accelerometer数据。它一直给我这个错误

package com.thawda.mm;

public class RCService extends Service
{

    private static final String LOGTAG2 = "RCService";
    private boolean isTaking =false;

    public void onCreate()
    {

        mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
        tMgr =(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);

        Intent battery = this.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

        int level = battery.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
        int scale = battery.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

        batteryPct = level / (float)scale;

        createFile();       
        myTimer();

        Toast.makeText(this, "The Program Threat has created....", Toast.LENGTH_LONG).show();

        Log.i(LOGTAG2,"ACC Service Running");       

    }
    @Override
    public void onDestroy()
    {
        super.onDestroy();
        closeFile();
        updateTimer.cancel();
        mSensorManager.unregisterListener(mListener);
        Toast.makeText(this, "Service Destroyed...", Toast.LENGTH_LONG).show();
    }
    @Override

    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }


    private SensorEventListener mListener = new SensorEventListener(){

        public void onAccuracyChanged(Sensor sensor, int accuracy)
        {
            // TODO Auto-generated method stub

        }
        @Override
        public void onSensorChanged(SensorEvent event) 
        {
            // TODO Auto-generated method stub

            String data3;
            //Date unixTime = new Date();
            x=event.values[0];
            y=event.values[1];
            z=event.values[2];
            //      data3 = String.format(" %1$1.4f",
            //                x);
            //      Log.i(LOGTAG2,data3);   

            //TIME = event.timestamp;
            //  TIME2 = unixTime.getTime();







        }
    };


    public void createFile()
    {
        String noTemp = tMgr.getDeviceId();
        File rootPath=new File(Environment.getExternalStorageDirectory()+"/MM_ACC/");
        String filepath =Environment.getExternalStorageDirectory()+"/MM_ACC/";
        File myFile = new File(filepath);

        String NAME = noTemp+"_"+DateFormat.format("yyyyMMdd-hhmmss", new Date())+"_MM_ACC_"+counter+".txt";        
        if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
        {
            Toast.makeText(this, "Cannot use storage", Toast.LENGTH_SHORT).show();
            //need to add about finish
            Log.i(LOGTAG2,"Passed usage of external storage");
            return;
        }

        //Create a new directory on External storage
        if(!rootPath.exists())
        {
            rootPath.mkdirs();
        }

        if(!myFile.isDirectory())
            myFile.mkdir();

        myFile = new File(filepath+NAME);
        try
        {
            myFile.createNewFile();
            fOut = new FileOutputStream(myFile);
            inChannel = fOut.getChannel();
            myOutWriter=new OutputStreamWriter(fOut);
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }
    public void WriteFile()
    {
        try
        {
            String data2;
            Date unixTime = new Date();
            TIME2 = unixTime.getTime();

            data2 = String.format(", %1$1.4f, %2$1.4f, %3$1.4f",
                    x, y, z);
            myOutWriter.write(TIME2+ data2 +"\r\n"); // fix the time

        }
        catch(FileNotFoundException e)
        {
            e.printStackTrace();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }

    public void closeFile()
    {
        try
        {
            myOutWriter.close();
            inChannel.close();
            fOut.flush();
            fOut.close();
        }

        catch (IOException e)
        {
            e.printStackTrace();
        }
    }


    public void myTimer()
    {
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

        //  IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
        //  registerReceiver(mReceiver, filter);
        // mSensorManager.registerListener(mListener, mAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);  //(*need to fix for highest accuracy
        updateTimer=new Timer("Update");

        // startlocation();
        updateTimer.scheduleAtFixedRate(new TimerTask() 
        {

            public void run()
            {
                WriteFile();
                try 
                {
                    //Log.d(LOGTAG2,"Timer 1 just ran");
                    filesize=inChannel.size();
                    if(filesize>100000)
                    {
                        counter++;
                        closeFile();
                        createFile();
                    } 
                }

                catch (IOException e) 
                {
                    // TODO Auto-generated catch block 
                    e.printStackTrace();
                }

            }
        }, 0, 100);
    }


    public boolean isTaking()
    {
        return isTaking;
    }
}

以下是我得到的错误

AndroidRuntime(4708): java.lang.NullPointerException
AndroidRuntime(4708):   at com.thawda.mm.RCService.WriteFile(RCService.java:196)
AndroidRuntime(4708):   at com.thawda.mm.RCService$2.run(RCService.java:241)
AndroidRuntime(4708):   at java.util.Timer$TimerImpl.run(Timer.java:284)

这些是我在公共类RCService extends Service

下的初始值

SensorManager mSensorManager;
Sensor mAccelerometer, mField;
TelephonyManager tMgr;
FileOutputStream fOut;
OutputStreamWriter myOutWriter;
FileChannel inChannel;
long filesize =0;
long counter=0;
public long TIME2;
float x,y,z;
float Azimuth, Pitch, Roll;
public long TIME,TIME3; 
private float[] mGravity;
private float[] mMagnetic;
public float batteryPct;
Timer updateTimer;

private static final String LOGTAG2 = "RCService";
private boolean isTaking =false;

Answer 1

我不知道为什么它解决了这个问题。我工厂重置了我的手机，现在它工作得非常好。我不知道为什么。