When does Application's onCreate() method get called?

Question

In my Android application, I have a DefaultApplication class which extends android.app.Application, and in its onCreate() I bind some services which will be used by my other Activities in this app.

Also I have a BroadcastReceiver which listens and receives C2DM Messages. When this receiver receives a message when the application is not running, it will fire a dialog which shows the upcoming message and it will start an Activity of my application.

My question is, when I start an activity without any interaction with DefaultApplication, will my DefaultApplication's onCreate() get called because an Activity of that application has started?

Here are the definition and Manifest of my DefaultApplication:

public class DefaultApplication extends Application {

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

        doBindService();

    }

    void doBindService() {

        // Establish a connection with the service. We use an explicit
        // class name because we want a specific service implementation that
        // we know will be running in our own process (and thus won't be
        // supporting component replacement by other applications).

        bindService(new Intent(DefaultApplication.this, SocketService.class),
                socketServiceConnection, Context.BIND_AUTO_CREATE);

        mIsBound = true;
    }

    void doUnbindService() {
        if (mIsBound) {
            // Detach our existing connection.
            unbindService(socketServiceConnection);
            mIsBound = false;
        }
    }
}

Manifest looks like this:

<application android:icon="@drawable/icon" android:label="@string/app_name"
        android:name="com.mypackage.DefaultApplication"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
        android:debuggable="true">
<service android:name="com.mypackage.services.SocketService"></service>
<activity android:name="TestActivity"
            android:screenOrientation="landscape"></activity>
</application>

I don't unserstand why you extend `Application`? Shouldn't you extend `Activity`? — Caner, Oct 07 '11 at 11:25
@LAS_VEGAS In the rest of my DefaultApplication I store some data and define some methods which are used Application-wide. I copied only a part of it to here. — Yasin YILDIRIM, Oct 07 '11 at 11:44

score 50 · Accepted Answer · answered Oct 07 '11 at 11:26

50

Only the first time.

When Activity is started and application is not loaded, then both onCreate() methods will be called.

But for subsequent starts of Activity, the onCreate() of application will not be called.

answered Oct 07 '11 at 11:26

Peter Knego

79,991
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Not strictly true. [Paul's answer explains a bit more, including a useful link.](http://stackoverflow.com/a/28498115/383414) – Richard Le Mesurier Aug 22 '16 at 10:56
In my case, onCreate method of application class is only being called when I install the app in mobile, it does not being invoked every time when I kill the app and restart it. – Shubham Mogarkar May 04 '22 at 07:35

score 36 · Answer 2 · edited Dec 30 '13 at 23:24

You can find an official answer when onCreate is called here.

Called when the application is starting, before any activity, service, or receiver objects (excluding content providers) have been created. Implementations should be as quick as possible (for example using lazy initialization of state) since the time spent in this function directly impacts the performance of starting the first activity, service, or receiver in a process. If you override this method, be sure to call super.onCreate().

score 20 · Answer 3 · edited May 23 '17 at 12:16

20

Note that if any service is defined to run in other process e.g. with android:process= then Application's onCreate() will be called again for that process.

For example see Android Application class method onCreate being called multiple times

edited May 23 '17 at 12:16

Community

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1

answered Feb 13 '15 at 11:01

Paul Verest

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When does Application's onCreate() method get called?

3 Answers3

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