Question

I am attempting to get my android to launch an activity when it registers a Bluetooth connection, I have all the proper permissions and this code runs fine up to the point that it needs to launch the intent. After that it crashes out. Right now I do not have a logcat for this as its on a live test on my phone.

So, lets play another game of “How do I fix this?”

public class detectService extends Service {

public void onCreate() {
    IntentFilter filter1 = new IntentFilter(
            BluetoothDevice.ACTION_ACL_CONNECTED);
    this.registerReceiver(mReceiver, filter1);
    Toast.makeText(this, "Starting Service!", Toast.LENGTH_LONG).show();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return START_STICKY;
}

// The BroadcastReceiver that listens for bluetooth broadcasts
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        BluetoothAdapter device = intent
                .getParcelableExtra(BluetoothDevice.ACTION_ACL_CONNECTED);

        if (device.equals(action)) {
            // Device is now connected
            // Start Second Activity
            Intent otherIntent = new Intent(detectService.this,
                    otherClass.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(otherIntent);
        }
    };
};
@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}
}

Thanks to the help of someone on here I now have logcat on my phone! Here is a copy of the errors:

E/AndroidRuntime(  567): FATAL EXCEPTION: main
E/AndroidRuntime(  567): java.lang.RuntimeException: Error receiving broadcast Intent { act=android.bluetooth.device.action.ACL_CONNECTED (has extras) } in lionsimages.com.bluetoothalert.detectService$1@4051ad68
E/AndroidRuntime(  567):    at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:722)
E/AndroidRuntime(  567):    at android.os.Handler.handleCallback(Handler.java:587)
E/AndroidRuntime(  567):    at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime(  567):    at android.os.Looper.loop(Looper.java:130)
E/AndroidRuntime(  567):    at android.app.ActivityThread.main(ActivityThread.java:3683)
E/AndroidRuntime(  567):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(  567):    at java.lang.reflect.Method.invoke(Method.java:507)
E/AndroidRuntime(  567):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
E/AndroidRuntime(  567):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)
E/AndroidRuntime(  567):    at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(  567): Caused by: java.lang.NullPointerException
E/AndroidRuntime(  567):    at lionsimages.com.bluetoothalert.detectService$1.onReceive(detectService.java:39)
E/AndroidRuntime(  567):    at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:709)
E/AndroidRuntime(  567):    ... 9 more

Answer 1

In your onReceive() method you do this:

   BluetoothAdapter device = intent
            .getParcelableExtra(BluetoothDevice.ACTION_ACL_CONNECTED);

But there is no extra with that name in this broadcast Intent. If you want to get the device from the Intent then you need this instead:

   BluetoothDevice device = intent
            .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

However, if I look at your code you seem to only want to check if the Intent ACTION is ACTION_ACL_CONNECTED. If that is all you want to do, then use this code instead:

public void onReceive(Context context, Intent intent) {
    String action = intent.getAction();

    if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
        // Device is now connected
        // Start Second Activity
        Intent otherIntent = new Intent(detectService.this,
                otherClass.class);
        // NOTE: I changed "intent" to "otherIntent" in the following line as well!
        otherIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(otherIntent);
    }
};