Android Call Intent Null pointer exception

Question

Im at my wits end here. I have a Class which Implements the OnClickListener cous i need the same action on Buttons accros my Application. This used to work just fine. But since I added some functionality by getting some needed data from the app preferences. startActivity throws a null pointer exception.
Here is the class:

//Imports public class CallClickListener extends Activity implements View.OnClickListener { protected AppPreferences appPrefs; String contactPersonName; String contactPersonTelephone; String name; public CallClickListener(Context context){ Log.d("TRACE", "init CallClick"); appPrefs = new AppPreferences(context); try { JSONObject object = appPrefs.getConsultantObject(); contactPersonName = object.getString("contactPersonName"); contactPersonTelephone = object.getString("contactPersonTelephone"); name = object.getString("name"); } catch (JSONException e) { e.printStackTrace(); } } @Override public void onClick(View view) { final View v = view; AlertDialog.Builder alert = new AlertDialog.Builder(view.getContext()); alert.setTitle("Anrufen"); alert.setMessage("Kontakt für " + name + ", " + contactPersonName + " anrufen"); alert.setPositiveButton("Anrufen", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Intent callIntent = new Intent(Intent.ACTION_CALL); callIntent.setData(Uri.parse("tel:"+contactPersonTelephone)); startActivity(callIntent);// this line throws the exception } }); alert.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(v.getContext(), "Abbruch", Toast.LENGTH_SHORT).show(); } }); alert.show(); } }

The Strings are all there from appPrefs, i also tried with hardcoding a phonenumber just incase. the Alert works fine, but as soon as i hit the positive Button, the app crashes
I add the Listener like this:

bCall.setOnClickListener(new CallClickListener(getApplicationContext()));

I added the necessary Call permissions.

I'm fairly new to Android dev, what am I missing?

Sam · Accepted Answer · 2013-05-25 09:55:41Z

Do this.... make the context object that you passed in the constructor into a field variable. and change startActivity to context.startActivity. It will work then.

EDIT: Highlighting the full solution.

bCall.setOnClickListener(new CallClickListener(getApplicationContext()));

should be changed to YourActivityClass.this instead of getApplicationContext.

Start Activity in the same task does not work with a context object that is not an Activity. So you need to either change the context to Activity or you start the activity in a new task. Also without calling startActivity on the context provided to your constructor you were getting the NPE because your CallClickListerner has no context.

@M4tchB0X3r i just tried your code by harcoding the number. the alertdialog works. on clicking the button it does make a call. i am not sure why you are getting NPE
bCall.setOnClickListener(new CallClickListener(getApplicationContext())); should be YourActivityClass.this instead of getApplicationContext. Try that.
srym not quite the same, now i gget this error! "Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?" not sure what that means
@SamarthJain i did suggest the same before but was not sure. so edited my answer again. coz he says alertdialog works

Community · Accepted Answer · 2017-05-23 12:05:24Z

Use activity context. Also check if you have initialized bCall. If you have not you will get NullPointerException.

 bCall.setOnClickListener(ActivityName.this);

Also check this link to know when to use activity context and when to use application context

When to call activity context OR application context?

Edit:

Make sure you have added permission in manifest file

 <uses-permission android:name="android.permission.CALL_PHONE" />

For reference use the below. My Class extends Activity

 Button b= (Button) findViewById(R.id.button1); b.setOnClickListener(new OnClickListener() { @Override public void onClick(View v1) { // TODO Auto-generated method stub final View v = v1; AlertDialog.Builder alert = new AlertDialog.Builder(v.getContext()); alert.setTitle("Anrufen"); alert.setMessage("Kontakt für " ); alert.setPositiveButton("Anrufen", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Intent callIntent = new Intent(Intent.ACTION_CALL); callIntent.setData(Uri.parse("tel:8095992052")); startActivity(callIntent);// this line throws the exception } }); alert.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialogInterface, int i) { Toast.makeText(v.getContext(), "Abbruch", Toast.LENGTH_SHORT).show(); } }); alert.show(); } });

Thnaks for the quick reply. I Obviously assign the button to a resource first. But when i try your code, i get the error 'CallClickListener' is not an enclosing class
I use the application context to get the application prefferences
Yes i have. Like i said it used to work. but since implementing the dynamic strings it crashes
@M4tchB0X3r log this contactPersonTelephone and check whether this is null or not

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