Android java.lang.IllegalArgumentException: Service not registered

I have a setup that looks something like this:

class MyFragment implements SomeEventListener {

    Application mAppContext;    

    boolean mBound;
    boolean mDidCallUnbind;
    MyIBinder mBinder;
    ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            mBound = true;
            mBinder = (MyIBinder) service;
            mBinder.getThings();...
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            mDidCallUnbind = false;
            mBound = false;
            mBinder = null;
        }
    };

    ...

    @Override
    public void onSomeEvent() {
        mAppContext.bindService(...);
    }

    void unbindService() {
        if (mBound && !mDidCallUnbind) {
            mDidCallUnbind = true;
            mAppContext.unbindService(mConnection);
        }
    }

    @Override
    public void onPause() {
        unbindService();
        super.onPause();
    }
}

However, I am still seeing the error in the title from time to time: java.lang.IllegalArgumentException: Service not registered being generated when unbindService() is called. Am I missing something silly, or is there more going on? I should note that there may be more than one of this same fragment in existence.

Edit

Since no one actually seems to be reading the code, let me explain. unbindService() does not call Context.unbindService(ServiceConnection) unless the service is bound (mBound) and it had not previously been called before the onServiceDisconnected(...) callback was hit from a possible previous call to unbindService().

That in mind, are there any cases where Android will unbind your service for you such that the service would become unbound but onServiceDisconnected would not be called thus leaving me in a stale state?

Also, I am using my Application context to do the initial binding. Assume something like:

@Override
public void onCreate() {
    mApplication = getContext().getApplicationContext();
}

Solution 1:

Use mIsBound inside doBindService() and doUnbindService() instead of in the ServiceConnection instance.

ServiceConnection mConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder service) {
        mBinder = (MyIBinder) service;
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {
        mBinder = null;
    }
}; 

...

public void doBindService() {
    mIsBound =bindService(new Intent(this, MyService.class),
        mConnection, Context.BIND_AUTO_CREATE); 
}

public void doUnbindService() {
    if (mIsBound) {
        unbindService(mConnection);
        mIsBound = false;
    }
}

This is how it's done in http://developer.android.com/reference/android/app/Service.html

Solution 2:

I realize this question has already been answered. But I think there is reason to go into why people are making this mistake.

The issue is really with the training docs. http://developer.android.com/reference/android/app/Service.html shows a correct implementation while https://developer.android.com/guide/components/bound-services.html in the 'ActivityMessenger' shows a Very INCORRECT implementation.

In the 'ActivityMessenger' example onStop() could potentially be called before the service has actually been bound.

The reason for this confusion is they are using the bound service boolean to mean different things in different examples. (mainly, was bindService() called OR is the Service actually connected)

In the correct examples where unbind() is done based on the value of the bound boolean, the bound boolean indicates that the bindService() was called. Since it's queued up for main thread execution, then unbindService() needs to be called (so queued to be executed), regardless of when (if ever) onServiceConnected() happens.

In other examples, such as the one in http://developer.android.com/reference/android/app/Service.html. The bound indicates that the Services is Actually bound so that you can use it and not get a NullPointerException. Note that in this example, the unbindService() call is still made and the bound boolean doesn't determine whether to unbind or not.

Solution 3:

java.lang.IllegalArgumentException: Service not registered means that you weren't bound to service when unbindService() was called.

So in your case, onSomeEvent() was never called before call to unbindService() in onPause()

Solution 4:

Another possible reason for this exception might be that unbindService is called by the wrong Context. Because services can be bound not only by Activities, but also by other instances inherited by Context (with the exception of BroadcastReceivers), even by other Services, be sure that unbindService is called by the context that has bound the Service and not by the bound Service itself. This would yield directly the above exception "Service not registered".

Solution 5:

Reason?

If in your Activity, unbindService() gets called before bindService() then you will get this IllegalArgumentException.

How to avoid it?
It's simple. You would not need a boolean flag if you bind and unbind service in this order.

Solution 1:

Bind in onStart() and unbind in onStop()

Your Activity {

    @Override
    public void onStart()
    {
        super.onStart();
        bindService(intent, mConnection , Context.BIND_AUTO_CREATE);
    }

    @Override
    public void onStop()
    {
        super.onStop();
        unbindService(mConnection);
    }

 } 

Solution 2:
Bind in onCreate() and unbind in onDestroy()

 Your Activity {

    @Override
    public void onCreate(Bindle sis)
    {
        super.onCreate(sis);
        ....
        bindService(intent, mConnection , Context.BIND_AUTO_CREATE);
    }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
        unbindService(mConnection);
    }         

 }

Relevant Link:

Android official documentation suggests that
If you need to interact with the service only while your activity is visible then go with Solution1.
If you want your activity to receive responses even while it is stopped in the background then go with Solution2.