How to execute code when application is closing?

Question

I am a Junior and I encounter a problem.

I am using Realm on Android (Java) and I would like to delete the data in my local BDD when it is closing. I always finish my activity before starting a new one and I never know what will be the last activity before user decided to close app.

Is there a way to execute code when app is closing?

EDIT

Here's my code, thanks to @Mohanad

public class ApplicationClass extends Application {

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

    Realm.init(this);

    RealmConfiguration mRealmConfig = new RealmConfiguration.Builder()
            .schemaVersion(1)
            .migration(new RealmMigrations())
            .inMemory()
            .build();

    Realm.setDefaultConfiguration(mRealmConfig);

    registerActivityLifecycleCallBack();

    Log.i("XXX", "I've been created");

}

public void registerActivityLifecycleCallBack() {

    ActivityLifecycleCallbacks mActivity = new ActivityLifecycleCallbacks() {
        int mCounter = 0;

        @Override
        public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
            mCounter++;
            Log.i("XXX", "I'm called again and again");
        }

        @Override
        public void onActivityStarted(Activity activity) {

        }

        @Override
        public void onActivityResumed(Activity activity) {

        }

        @Override
        public void onActivityPaused(Activity activity) {

        }

        @Override
        public void onActivityStopped(Activity activity) {

        }

        @Override
        public void onActivitySaveInstanceState(Activity activity, Bundle outState) {

        }

        @Override
        public void onActivityDestroyed(Activity activity) {
            mCounter--;

            if (mCounter == 0) {
                Realm mRealm  = Realm.getDefaultInstance();

                mRealm.close();
            }
        }
    };
}
}

Answer 1

Steps:

1.) use inMemory() configuration

RealmConfiguration config = new RealmConfiguration.Builder()
                                    .inMemory()
                                    .build();

2.) Call realm.init() in Application.onCreate(), set the default configuration as usual, and afterwards, initialize/close Realm like this:

public class MyActivity extends AppCompatActivity {
    private Realm realm;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        realm = Realm.getDefaultInstance();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        realm.close();
    }
}

Now when Realm is closed on all threads and you are quitting the app (or the app is killed), the Realm will be deleted.