The Problem
One day it was just there. A mischievous NullPointerException causing, eh, mischief. It was fairly easy to provoke with my application but for some reason my code was not part of the stacktrace.

12-07 14:42:52.722 E/AndroidRuntime(18421): FATAL EXCEPTION: main
12-07 14:42:52.722 E/AndroidRuntime(18421): java.lang.NullPointerException
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1064)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1081)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.os.Handler.handleCallback(Handler.java:587)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.os.Handler.dispatchMessage(Handler.java:92)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.os.Looper.loop(Looper.java:130)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at android.app.ActivityThread.main(ActivityThread.java:3701)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at java.lang.reflect.Method.invokeNative(Native Method)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at java.lang.reflect.Method.invoke(Method.java:507)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)
12-07 14:42:52.722 E/AndroidRuntime(18421): 	at dalvik.system.NativeStart.main(Native Method)

I fretted. I winced. I even felt a slight irritation coming on.

The Solution
In the end I found out the reason behind the mysterious NullPointerException. My application is binding to a Service and it turns out that the ContextWrapper.bindService()-method can’t take a null as its ServiceConnection parameter.

ContextWrapper.bindService():
public boolean bindService (Intent service, ServiceConnection conn, int flags)
Connect to an application service, creating it if needed.

Instead of throwing a helpful IllegalArgumentException it forwards the erroneous null-parameter into the innards of The Android Service Beast. That part is then unable to use it and throws a NullPointerException instead together with its own stacktrace which your code is not a part of.

The Summary
In short, make sure you don’t pass bindService() a null as the ServiceConnection parameter or you will get an unknown NullPointerException which is hard to track down.