Launching an Activity from a Service

Question

When I am trying to launch a call activity from a Service, I get a NullPointerException. Here is my code:

Intent callIntent = new Intent(Intent.ACTION_CALL);
callIntent.setData(Uri.parse("tel:" + number));
callIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(callIntent);

I get the exception on the startActivity line.

I tried to use getApplication.startActivity and getApplicationContext.startActivity but no luck.

Any ideas?

edit : Maybe some usefull info: I am trying to create a service that will run on the background and scan sensor data, when a certain signal is given i would like to maken an automated call to a number.

edit : full adb error code:

03-31 09:04:10.214: ERROR/AndroidRuntime(1896): Uncaught handler: thread main exiting due to uncaught exception
03-31 09:04:10.226: ERROR/AndroidRuntime(1896): java.lang.RuntimeException: Unable to instantiate service dfz.epilepsiedetector.services.DetectionService: java.lang.NullPointerException
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2668)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.app.ActivityThread.access$3100(ActivityThread.java:116)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1846)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.os.Looper.loop(Looper.java:123)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.app.ActivityThread.main(ActivityThread.java:4203)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at java.lang.reflect.Method.invokeNative(Native Method)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at java.lang.reflect.Method.invoke(Method.java:521)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at dalvik.system.NativeStart.main(Native Method)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896): Caused by: java.lang.NullPointerException
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.content.ContextWrapper.getPackageName(ContextWrapper.java:120)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.content.ComponentName.<init>(ComponentName.java:75)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.content.Intent.<init>(Intent.java:2302)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at dfz.epilepsiedetector.services.DetectionService.<init>(DetectionService.java:35)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at java.lang.Class.newInstanceImpl(Native Method)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at java.lang.Class.newInstance(Class.java:1472)
03-31 09:04:10.226: ERROR/AndroidRuntime(1896):     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2665)

edit Trimmed class code:

public class DetectionService extends IntentService implements SensorEventListener
{   
 private SensorManager mSensorManager;
 private Sensor mAccelerometer;
 private boolean hasSeizure = false;

 private final int POLLS_PER_SECOND = 10;

 public DetectionService()
 {
 super("EpilepsionDetectionService");

 Intent callIntent = new Intent(DetectionService.this,
 InformationActivity.class);
 callIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        
 getApplication().startActivity(callIntent);
}

xyz is your service; http://stackoverflow.com/questions/3456034/how-to-start-an-activity-from-a-service ; some guy did the same with you. do you have a permission in ANdroidManifest ? — LTEHUB, Mar 31 '11 at 08:55
@DO Ngoc Tuan i am calling the intent in that way, the problem is that its not working! i keep recieveing `NullPointerException` — nldev, Mar 31 '11 at 08:59
i did the same with you before: get the value of Sensor, if(condition) call new Activity. no problem. ; - - -- - - - - public class MyclassService extends MapActivity implements SensorEventListener{ — LTEHUB, Mar 31 '11 at 09:45
Yes i know, i am also able to react to sensors and launch activity's but just not from a background service, what you mention is a MapActivity. Ofcourse they both have a context but when I try to get it from the service it returns null. — nldev, Mar 31 '11 at 09:57
MapActivity is in my situation;or you can see here , call the activity from Service, it doesnot solve your problem but it give you some idea : - - - - -http://stackoverflow.com/questions/2735927/running-activity-from-remote-service — LTEHUB, Mar 31 '11 at 11:37

Uday · Answer 1 · 2011-03-31T09:22:54.637

1

You have to get that context from an activity where you calling a service.. from that you have to call`

Intent callIntent = new Intent(Intent.ACTION_CALL);
callIntent.setData(Uri.parse("tel:" + number));


 callIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 context.startActivity(callIntent);

edit:

callIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplication().startActivity(callIntent);`

`

hope it helps...

edited Mar 31 '11 at 09:22

answered Mar 31 '11 at 08:49

Uday

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Do you also know where i can get that context? – nldev Mar 31 '11 at 09:03

score 0 · Answer 2 · answered Mar 31 '11 at 08:41

0

You can try:

getBaseContext().startActivity(callIntent);

Or use:

this.startActivity(callIntent);

answered Mar 31 '11 at 08:41

vendor

1,854
13
8

@vendor Both return me a `NullPointerException` – nldev Mar 31 '11 at 08:45
@nldev Can you post the full log from adb. – vendor Mar 31 '11 at 08:58
@vendor I posted it in the question – nldev Mar 31 '11 at 09:07
@nldev Do you include the right call permission in the android manifest? – vendor Mar 31 '11 at 09:17
@vendor Yes it all works from a normal activity, just not from the service... ? – nldev Mar 31 '11 at 09:20
@nldev If you code is not big, you can post it, or trim some part of it, because the above code snippet looks good to me. – vendor Mar 31 '11 at 09:29
@vendor I posted the code in the main question, i have a meeting now so i will be back in 1 1/2 hours – nldev Mar 31 '11 at 10:04

score 0 · Answer 3 · answered Apr 28 '11 at 08:51

0

For future reference:

The problem went away when inhereting directly from Service as opposed to Intent service.

Hop this helps!

answered Apr 28 '11 at 08:51

nldev

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score 0 · Answer 4 · edited Oct 26 '12 at 04:54

0

Move the code out of the constructor and into the onCreate() method. The long and short of it is that the class hasn't been totally initialized yet and is causing the NullPointerException.

edited Oct 26 '12 at 04:54

wattostudios

8,666
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answered Feb 16 '12 at 22:30

Dallas

1

score -1 · Answer 5 · edited Oct 26 '12 at 05:17

-1

Call the intent in the onStart method of the service instead of the onCreate method.

edited Oct 26 '12 at 05:17

user

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answered Oct 26 '12 at 04:58

Anirudh

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Launching an Activity from a Service

5 Answers5