Register Application Class in Android

Application is the base class for maintaining global application state. You can provide your own implementation by creating a subclass and specifying the name of this subclass as the android:name attribute in <application> of AndroidManifest.xml. The Application class, or your subclass of the Application class, is instantiated before any other class when the process for your application/package is created.

Application Subclass

Below example shows an example of subclass of Application class. This class create application shortcut based on android version.

public class App extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        if (Build.VERSION.SDK_INT >= 25) {
            createShortcut();
            if(Build.VERSION.SDK_INT >=26){
                pinShortcut();
            }

        }else{
            removeShortcuts();
        }
    }

    @TargetApi(25)
    private void createShortcut() {
        ShortcutManager sM = getSystemService(ShortcutManager.class);

        Intent intent1 = new Intent(getApplicationContext(), MainActivity.class);
        intent1.setAction(MyUtils.ACTION_START_CAPTURE_NOW);

        ShortcutInfo shortcut1 = new ShortcutInfo.Builder(this, "shortcut_capture_now")
                .setIntent(intent1)
                .setShortLabel("Start Now")
                .setLongLabel("Start Service Now")
                .setDisabledMessage("Permission Denied, open app to resolve it")
                .setIcon(Icon.createWithResource(this, R.mipmap.ic_launcher))
                .build();

        sM.setDynamicShortcuts(Arrays.asList(shortcut1));

    }

    @RequiresApi(api = Build.VERSION_CODES.O)
    private void pinShortcut() {
        ShortcutManager shortcutManager = getSystemService(ShortcutManager.class);
        if (shortcutManager.isRequestPinShortcutSupported()) {

            ShortcutInfo pinShortcutInfo = new ShortcutInfo
                    .Builder(getApplicationContext(), "shortcut_capture_now")
                    .build();

            Intent pinnedShortcutCallbackIntent =
                    shortcutManager.createShortcutResultIntent(pinShortcutInfo);

            PendingIntent successCallback = PendingIntent.getBroadcast(getApplicationContext(), 0,
                    pinnedShortcutCallbackIntent, 0);
            shortcutManager.requestPinShortcut(pinShortcutInfo, successCallback.getIntentSender());
        }
    }

    @TargetApi(25)
    private void removeShortcuts() {
        ShortcutManager shortcutManager = getSystemService(ShortcutManager.class);
        shortcutManager.disableShortcuts(Arrays.asList("shortcut_capture_now"));
        shortcutManager.removeAllDynamicShortcuts();
    }
}

Subclass defined above must be declared in AndroidManifest.xml. Following example illustrate how to declare application subclass in manifest file.

 <?xml version="1.0" encoding="utf-8"?>
<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.aphalaprepsunaa.recorder">


    <application
        android:name=".App"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity
            android:name=".ui.activities.MainActivity"
            android:configChanges="keyboardHidden|orientation"
            android:windowSoftInputMode="adjustPan">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

android:label is the name that will show up on emulators and real devices as you’ve observed. android:name is the name of a class (here App) implementing the android.app.Application for this package. This attribute is used when you have a custom class that extends Application that you want to use.