System services not available to Activities before onCreate(), but no properties instantiated

Question

I am trying to create a service which checks if the device has an active internet connection and reports it. I have absolutely no clue what's wrong with my code.

I know this question has been asked many times, but most answers, like this, state

that one cannot create an activity using the new keyword (see this post);
that properties which are instantiated also are the cause of the problem (see this post).

Now as far as I know, I avoided forementioned causes. This is my simplified code:

MyActivity

public MyActivity extends SuperActivity {

    // No properties are instantiated
    // No onCreate(Bundle) method

}

SuperActivity

public SuperActivity extends Activity {

    ApplicationManager appMgr;
    UIManager uiMgr;
    // No properties are instantiated, only declared

    @Override
    public void onCreate(Bundle savedInstance) {
        super.onCreate(savedInstance);

        this.appMgr = new ApplicationManager(this);
        this.appMgr.getUIManager().init();
    }
}

ApplicationManager

public ApplicationManager {

    // No properties are instantiated
    SuperActivity activity;
    Thread serviceThread;
    UIManager uiMgr;

    ApplicationManager(SuperActivity activity) {
        this.activity = activity;
        this.uiMgr = new UIManager(this);
    }

    void initService() {
        this.serviceThread = new Thread(new Runnable() {

            @Override
            public void run() {
                Intent intent = new Intent(getActivity(), ConnectionService.class);
                intent.putExtra("CONTEXT", getActivity());
                intent.putExtra("ALLOW_MOBILE_CONNECTION", true);
                getActivity().startService(intent);
            }
        });
    }

    void startService() {
        this.serviceThread.start();
    }

    UIManager getUIManager() {
        return this.uiMgr;
    }

    SuperActivity getActivity() {
        return this.activity;
    }
}

UIManager

public class UIManager {

    // No properties are instantiated

    void init() {
        getApplicationManager().initService();
        getApplicationManager().startService(); // <-- FIRST MARKER,
                                                //     see below
    }

}

ConnectionService

public class ConnectionService {

    @Override
    protected Bundle onHandleIntent(Intent intent) {
        Bundle params = intent.getExtras();
        Bundle bundle = new Bundle();
        Context cntxt = (Context) params.getSerializable("CONTEXT");
        try {
            boolean wifi =
                NetworkUtils.hasWifiCon(cntxt); // <-- SECOND MARKER,
                                                //     see below

            ...
        }
        catch (SocketException exc) { ... }
        return bundle;
    }
}

The error occurs on the line denoted by SECOND MARKER, which gets the system connection service and checks for wifi. This is the service which is not allowed to be called before onCreate().

Furthermore, if I remove or comment the line denoted by FIRST MARKER, the error is gone, but also, of course, the service is not started.

What could be the problem?

One problem is that your code will not compile. `ApplicationManager` does not have a `getActivity()` method. — CommonsWare, Jan 24 '15 at 16:53
@CommonsWare I forgot to add it, due to the process of simplifying the code. — MC Emperor, Jan 24 '15 at 16:55

score 2 · Accepted Answer · answered Jan 24 '15 at 16:39

2

You cannot pass around a Context by serializing it in a bundle.

In an IntentService which I assume your ConnectionService is, just use this for a valid Context.

answered Jan 24 '15 at 16:39

laalto

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System services not available to Activities before onCreate(), but no properties instantiated

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