threadid=1: thread exiting with uncaught exception (group=0x41cd1700)

Question

I am trying to run a thread on button click, but it force closes,

here is code,

package kulkarni.darpan.vtc;

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

Button btnRegister;
EditText emailRegister;
CheckBox enDisTracking;
Handler hand;
GPSTracker gps;
AsyncPostRequest asp;
AsyncRegisterDevice ard;
DeviceInfo di;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    gps = new GPSTracker(MainActivity.this);
    di = new DeviceInfo(MainActivity.this);
    asp = new AsyncPostRequest();
    ard = new AsyncRegisterDevice();

    btnRegister = (Button) findViewById(R.id.regButton);
    emailRegister = (EditText)findViewById(R.id.regEmail);
    enDisTracking = (CheckBox)findViewById(R.id.startTracking);
    btnRegister.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) { 
            //registerDevice();
            hand.postDelayed(run, 1000);
        }
    });
}

Runnable run = new Runnable() {

    public void run()
    {
        sendLocation();
    }

};

public void registerDevice(){

    String regEmail = emailRegister.getText().toString();
    String regUniqueID = di.getDeviceInfo();
    String regObj[] = new String[2];
    regObj[0] = regEmail;
    regObj[1] = regUniqueID;
    ard.execute(regObj);
}

public void sendLocation(){

    if(gps.canGetLocation()){

        double latitude = gps.getLatitude();
        double longitude = gps.getLongitude();
        String uniq = di.getDeviceInfo();
        String aobj[] = new String[3];
        aobj[0]=Double.toString(latitude);
        aobj[1]=Double.toString(longitude);
        aobj[2]=uniq;
        asp.execute(aobj);

        Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude +"\nIMEI: "+uniq, Toast.LENGTH_LONG).show();    

    }else{
        gps.showSettingsAlert();
    }
    hand.postDelayed(run, 20000);
}    
}

And here is log file,

02-19 17:57:29.115: D/Network(29198): Network
02-19 17:57:29.275: D/libEGL(29198): loaded /system/lib/egl/libEGL_mali.so
02-19 17:57:29.305: D/libEGL(29198): loaded /system/lib/egl/libGLESv1_CM_mali.so
02-19 17:57:29.310: D/libEGL(29198): loaded /system/lib/egl/libGLESv2_mali.so
02-19 17:57:29.315: E/(29198): Device driver API match
02-19 17:57:29.315: E/(29198): Device driver API version: 23
02-19 17:57:29.315: E/(29198): User space API version: 23 
02-19 17:57:29.315: E/(29198): mali: REVISION=Linux-r3p2-01rel3 BUILD_DATE=Wed Oct  9        21:05:57 KST 2013 
02-19 17:57:29.425: D/OpenGLRenderer(29198): Enabling debug mode 0
02-19 17:57:38.575: D/AndroidRuntime(29198): Shutting down VM
02-19 17:57:38.575: W/dalvikvm(29198): threadid=1: thread exiting with uncaught exception (group=0x41cd1700)
02-19 17:57:38.580: E/AndroidRuntime(29198): FATAL EXCEPTION: main
02-19 17:57:38.580: E/AndroidRuntime(29198): java.lang.NullPointerException
02-19 17:57:38.580: E/AndroidRuntime(29198):    at     kulkarni.darpan.vtc.MainActivity$2.onClick(MainActivity.java:41)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at     android.view.View.performClick(View.java:4475)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at android.view.View$PerformClick.run(View.java:18786)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at android.os.Handler.handleCallback(Handler.java:730)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at android.os.Looper.loop(Looper.java:176)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at android.app.ActivityThread.main(ActivityThread.java:5419)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at java.lang.reflect.Method.invokeNative(Native Method)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at java.lang.reflect.Method.invoke(Method.java:525)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
02-19 17:57:38.580: E/AndroidRuntime(29198):    at dalvik.system.NativeStart.main(Native Method)

Any solution on this problem?

Answer 1

You have not initialized Handler hand. You have only declare it. Make sure you initialize the Handler before using it.

hand = new Handler();

Have a look @

http://developer.android.com/reference/android/os/Handler.html