Null Pointer Exception in my Activity

Question

When I call this Activity, a Null Pointer Exception occurs. Why does this happen?

package com.andrd.gps;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class User_Detail_ListActivity extends Activity{
TransportData tdata;
private TextView drivernametxt,agetxt,addresstxt,liecencetxt,contactNotxt,driverTypetxt,truckNotxt,truckPermittxt,truckTypetxt,fromtxt,totxt;
Button editBtn,deleteBtn,cancelBtn;
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.user_list);


    drivernametxt = (TextView) findViewById(R.id.nameTextView);
    agetxt=(TextView) findViewById(R.id.ageTextView);
    addresstxt=(TextView) findViewById(R.id.addressTextView);
    liecencetxt=(TextView) findViewById(R.id.licenseNoTextView);
    contactNotxt=(TextView) findViewById(R.id.contactNoTextView);
    driverTypetxt=(TextView) findViewById(R.id.employmetnTypeTextView);
    truckNotxt=(TextView) findViewById(R.id.truckNoTextView);
    truckPermittxt=(TextView) findViewById(R.id.truckPermitTextView);
    truckPermittxt=(TextView) findViewById(R.id.truckTypeTextView);
    fromtxt=(TextView) findViewById(R.id.fromTextView);
    totxt=(TextView) findViewById(R.id.toTextView);

    editBtn =(Button) findViewById(R.id.editBtn);
    deleteBtn = (Button) findViewById(R.id.deleteBtn);
    cancelBtn = (Button) findViewById(R.id.cancelBtn);

    drivernametxt.setText(getIntent().getExtras().getString("DriverName"));
    agetxt.setText(getIntent().getExtras().getString("Age"));
    addresstxt.setText(getIntent().getExtras().getString("Address"));
    liecencetxt.setText(getIntent().getExtras().getString("LiecenseNo"));

    contactNotxt.setText(getIntent().getExtras().getString("ContactNo"));
    driverTypetxt.setText(getIntent().getExtras().getString("DriverType"));
    truckNotxt.setText(getIntent().getExtras().getString("TruckNo"));
    truckPermittxt.setText(getIntent().getExtras().getString("TruckPermit"));
    truckTypetxt.setText(getIntent().getExtras().getString("TruckType"));
    fromtxt.setText(getIntent().getExtras().getString("FromLocation"));
    totxt.setText(getIntent().getExtras().getString("ToLocation"));


    editBtn.setOnClickListener(new OnClickListener(){
        public void onClick(View v) {
            Intent intent = new Intent(User_Detail_ListActivity.this, EditUserDetailActivity.class);
            intent.putExtra("TruckNo", getIntent().getExtras().getString("TruckNo"));
            startActivity(intent);
        }

    });

    deleteBtn.setOnClickListener(new OnClickListener(){
        public void onClick(View v) {
            try {
                tdata.deleteUser(getIntent().getExtras().getString("TruckNo"));
                finish();
            } catch (Exception e) {
                Toast.makeText(getApplicationContext(), "database Error", Toast.LENGTH_LONG).show();
            }

        }

    });

    cancelBtn.setOnClickListener(new OnClickListener(){

        public void onClick(View v) {
            finish();
        }

    });
}
}

paste the stacktrace or at least tell us which line is throwing the exception please. — James.Xu, Apr 01 '11 at 03:40
04-01 09:12:20.609: ERROR/AndroidRuntime(646): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.andrd.gps/com.andrd.gps.User_Detail_ListActivity}: java.lang.NullPointerException — Mukesh Ninama, Apr 01 '11 at 03:46
@Mukesh:Please edit your post & paste the stack trace there.In this one can't able to understand at which line NullPointerException occurred. — Shashank_Itmaster, Apr 01 '11 at 03:49
Can you post the code for the onCreate method of the Activity you are trying to start? — Corey Sunwold, Apr 02 '11 at 01:20
possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Joel, Feb 16 '15 at 18:58

score 1 · Answer 1 · answered Apr 01 '11 at 03:51

1

Make sure that you add the activity to you Application Manifest

<activity android:name=".EditUserDetailActivity"></activity>

answered Apr 01 '11 at 03:51

Corey Sunwold

10,194
6
51
55

score 1 · Answer 2 · edited Apr 15 '17 at 04:02

1

Generally in Java the reasons for NullPointerException is:

you accessed the uninitialized variables.

But in this case you may not set the Extras in the previous Activity or your getString() method argument value maybe wrong

edited Apr 15 '17 at 04:02

OneCricketeer

179,855
19
132
245

answered Apr 01 '11 at 03:52

Balaji.K

8,745
5
30
39

score 0 · Answer 3 · answered Apr 15 '17 at 04:04

You never initialized truckTypetxt... You instead initialized this one twice.

truckPermittxt=(TextView) findViewById(R.id.truckPermitTextView);
truckPermittxt=(TextView) findViewById(R.id.truckTypeTextView);

But yet you use truckTypetxt

truckTypetxt.setText(getIntent().getExtras().getString("TruckType"));

score 0 · Answer 4 · answered Apr 01 '11 at 03:55

Hi Mukesh I thing you made a mistake in initializing the TextView.

Please check that you have initialized truckPermittxt twice. Initialize truckTypetxt there & then try using truckTypetxt.setText(getIntent().getExtras().getString("TruckType"));

This main reason of NullPointerException.

Null Pointer Exception in my Activity

4 Answers4