android remote service running in a separate process and call methods from onserviceconnected()

Question

I'm writing a service using AIDL to invoke methods remotely. I'm able to connect to the service successfully and also, invoke methods on it. However, if I try to invoke a method in onServiceConnected(), I get null pointer exception. Snippet of the code is below.

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
 Log.v(TAG, "service connected");
 serviceObj = <AIDL Interface>.Stub.asInterface(service)
 if(serviceObj != null) {
   serviceObj.getMyMethod(); // Throws Null Pointer Exception, why???
} 
}

Also, in manifest, I have defined the following property in the service tag:

android:process=":remote"

However, if I invoke serviceObj.getMyMethods() somewhere else, like on clicking a GUI button, I don't get such error and the methods returns successfully. In addition, if I remove the above ":remote" property, I don't get this error with the same code.

I guess this is the problem associated with running the app and service in different processes, but not able to figure out the exact cause. Any ideas?

Answer 1

Finally I figured it out. Some internal crash/null pointer exception was happening due to the fact that Context.startService() is an asynchronous call. While onStartCommand() was performing some tasks, a method invoked on serviceObj in parallel was crashing since it needed some initialization to happen first which was taking place in onStartCommand().