varunon9 · July 17, 2025 00:10 · mecoFarid · May 25, 2021 · Lee858 · Jul 27, 2021
diff --git a/AlwaysRunningAndroidService.md b/AlwaysRunningAndroidService.md
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="varunon9.me.dynamicwallpaper">

    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

    <application
        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">
        <receiver
            android:name=".MyReceiver"
            android:enabled="true"
            android:exported="false"></receiver>

        <service
            android:name=".MyService"
            android:enabled="true"
            android:exported="true" />

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

 </manifest>
diff --git a/MainActivity.java b/MainActivity.java
 package varunon9.me.dynamicwallpaper;

 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.content.ContextCompat;
 import androidx.work.ExistingPeriodicWorkPolicy;
 import androidx.work.PeriodicWorkRequest;
 import androidx.work.WorkManager;

 import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;

 import java.util.concurrent.TimeUnit;

 public class MainActivity extends AppCompatActivity {

    private String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate called");
        setContentView(R.layout.activity_main);
        startServiceViaWorker();
    }

    public void onStartServiceClick(View v) {
        startService();
    }

    public void onStopServiceClick(View v) {
        stopService();
    }

    @Override
    protected void onDestroy() {
        Log.d(TAG, "onDestroy called");
        stopService();
        super.onDestroy();
    }

    public void startService() {
        Log.d(TAG, "startService called");
        if (!MyService.isServiceRunning) {
            Intent serviceIntent = new Intent(this, MyService.class);
            ContextCompat.startForegroundService(this, serviceIntent);
        }
    }

    public void stopService() {
        Log.d(TAG, "stopService called");
        if (MyService.isServiceRunning) {
            Intent serviceIntent = new Intent(this, MyService.class);
            stopService(serviceIntent);
        }
    }

    public void startServiceViaWorker() {
        Log.d(TAG, "startServiceViaWorker called");
        String UNIQUE_WORK_NAME = "StartMyServiceViaWorker";
        WorkManager workManager = WorkManager.getInstance(this);

        // As per Documentation: The minimum repeat interval that can be defined is 15 minutes
        // (same as the JobScheduler API), but in practice 15 doesn't work. Using 16 here
        PeriodicWorkRequest request =
                new PeriodicWorkRequest.Builder(
                        MyWorker.class,
                        16,
                        TimeUnit.MINUTES)
                        .build();

        // to schedule a unique work, no matter how many times app is opened i.e. startServiceViaWorker gets called
        // do check for AutoStart permission
        workManager.enqueueUniquePeriodicWork(UNIQUE_WORK_NAME, ExistingPeriodicWorkPolicy.KEEP, request);

    }
 }
diff --git a/MyReceiver.java b/MyReceiver.java
 package varunon9.me.dynamicwallpaper;

 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.util.Log;

 import androidx.work.OneTimeWorkRequest;
 import androidx.work.WorkManager;

 public class MyReceiver extends BroadcastReceiver {
    private String TAG = "MyReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d(TAG, "onReceive called");

        // We are starting MyService via a worker and not directly because since Android 7
        // (but officially since Lollipop!), any process called by a BroadcastReceiver
        // (only manifest-declared receiver) is run at low priority and hence eventually
        // killed by Android.
        WorkManager workManager = WorkManager.getInstance(context);
        OneTimeWorkRequest startServiceRequest = new OneTimeWorkRequest.Builder(MyWorker.class)
                .build();
        workManager.enqueue(startServiceRequest);
    }
 }
diff --git a/MyService.java b/MyService.java
 package varunon9.me.dynamicwallpaper;

 import android.app.Notification;
 import android.app.NotificationChannel;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.Service;
 import android.content.Intent;
 import android.os.Build;
 import android.os.IBinder;
 import android.util.Log;

 import androidx.core.app.NotificationCompat;

 public class MyService extends Service {
    private String TAG = "MyService";
    public static boolean isServiceRunning;
    private String CHANNEL_ID = "NOTIFICATION_CHANNEL";

    public MyService() {
        Log.d(TAG, "constructor called");
        isServiceRunning = false;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "onCreate called");
        createNotificationChannel();
        isServiceRunning = true;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "onStartCommand called");
        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
                0, notificationIntent, 0);
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("Service is Running")
                .setContentText("Listening for Screen Off/On events")
                .setSmallIcon(R.drawable.ic_wallpaper_black_24dp)
                .setContentIntent(pendingIntent)
                .setColor(getResources().getColor(R.color.colorPrimary))
                .build();

        startForeground(1, notification);
        return START_STICKY;
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            String appName = getString(R.string.app_name);
            NotificationChannel serviceChannel = new NotificationChannel(
                    CHANNEL_ID,
                    appName,
                    NotificationManager.IMPORTANCE_DEFAULT
            );
            NotificationManager manager = getSystemService(NotificationManager.class);
            manager.createNotificationChannel(serviceChannel);
        }
    }

    @Override
    public void onDestroy() {
        Log.d(TAG, "onDestroy called");
        isServiceRunning = false;
        stopForeground(true);

        // call MyReceiver which will restart this service via a worker
        Intent broadcastIntent = new Intent(this, MyReceiver.class);
        sendBroadcast(broadcastIntent);

        super.onDestroy();
    }
 }
diff --git a/MyWorker.java b/MyWorker.java
 package varunon9.me.dynamicwallpaper;

 import android.content.Context;
 import android.content.Intent;
 import android.util.Log;

 import androidx.annotation.NonNull;
 import androidx.core.content.ContextCompat;
 import androidx.work.Worker;
 import androidx.work.WorkerParameters;

 public class MyWorker extends Worker {
    private final Context context;
    private String TAG = "MyWorker";

    public MyWorker(
            @NonNull Context context,
            @NonNull WorkerParameters params) {
        super(context, params);
        this.context = context;
    }

    @NonNull
    @Override
    public Result doWork() {
        Log.d(TAG, "doWork called for: " + this.getId());
        Log.d(TAG, "Service Running: " + MyService.isServiceRunning);
        if (!MyService.isServiceRunning) {
            Log.d(TAG, "starting service from doWork");
            Intent intent = new Intent(this.context, MyService.class);
            ContextCompat.startForegroundService(context, intent);
        }
        return Result.success();
    }

    @Override
    public void onStopped() {
        Log.d(TAG, "onStopped called for: " + this.getId());
        super.onStopped();
    }
 }
	<?xml version="1.0" encoding="utf-8"?>
	<manifest xmlns:android="http://schemas.android.com/apk/res/android"
	package="varunon9.me.dynamicwallpaper">

	<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

	<application
	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">
	<receiver
	android:name=".MyReceiver"
	android:enabled="true"
	android:exported="false"></receiver>

	<service
	android:name=".MyService"
	android:enabled="true"
	android:exported="true" />

	<activity android:name=".MainActivity">
	<intent-filter>
	<action android:name="android.intent.action.MAIN" />

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

	</manifest>
	package varunon9.me.dynamicwallpaper;

	import androidx.appcompat.app.AppCompatActivity;
	import androidx.core.content.ContextCompat;
	import androidx.work.ExistingPeriodicWorkPolicy;
	import androidx.work.PeriodicWorkRequest;
	import androidx.work.WorkManager;

	import android.content.Intent;
	import android.os.Bundle;
	import android.util.Log;
	import android.view.View;

	import java.util.concurrent.TimeUnit;

	public class MainActivity extends AppCompatActivity {

	private String TAG = "MainActivity";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	Log.d(TAG, "onCreate called");
	setContentView(R.layout.activity_main);
	startServiceViaWorker();
	}

	public void onStartServiceClick(View v) {
	startService();
	}

	public void onStopServiceClick(View v) {
	stopService();
	}

	@Override
	protected void onDestroy() {
	Log.d(TAG, "onDestroy called");
	stopService();
	super.onDestroy();
	}

	public void startService() {
	Log.d(TAG, "startService called");
	if (!MyService.isServiceRunning) {
	Intent serviceIntent = new Intent(this, MyService.class);
	ContextCompat.startForegroundService(this, serviceIntent);
	}
	}

	public void stopService() {
	Log.d(TAG, "stopService called");
	if (MyService.isServiceRunning) {
	Intent serviceIntent = new Intent(this, MyService.class);
	stopService(serviceIntent);
	}
	}

	public void startServiceViaWorker() {
	Log.d(TAG, "startServiceViaWorker called");
	String UNIQUE_WORK_NAME = "StartMyServiceViaWorker";
	WorkManager workManager = WorkManager.getInstance(this);

	// As per Documentation: The minimum repeat interval that can be defined is 15 minutes
	// (same as the JobScheduler API), but in practice 15 doesn't work. Using 16 here
	PeriodicWorkRequest request =
	new PeriodicWorkRequest.Builder(
	MyWorker.class,
	16,
	TimeUnit.MINUTES)
	.build();

	// to schedule a unique work, no matter how many times app is opened i.e. startServiceViaWorker gets called
	// do check for AutoStart permission
	workManager.enqueueUniquePeriodicWork(UNIQUE_WORK_NAME, ExistingPeriodicWorkPolicy.KEEP, request);

	}
	}
	package varunon9.me.dynamicwallpaper;

	import android.content.BroadcastReceiver;
	import android.content.Context;
	import android.content.Intent;
	import android.util.Log;

	import androidx.work.OneTimeWorkRequest;
	import androidx.work.WorkManager;

	public class MyReceiver extends BroadcastReceiver {
	private String TAG = "MyReceiver";

	@Override
	public void onReceive(Context context, Intent intent) {
	Log.d(TAG, "onReceive called");

	// We are starting MyService via a worker and not directly because since Android 7
	// (but officially since Lollipop!), any process called by a BroadcastReceiver
	// (only manifest-declared receiver) is run at low priority and hence eventually
	// killed by Android.
	WorkManager workManager = WorkManager.getInstance(context);
	OneTimeWorkRequest startServiceRequest = new OneTimeWorkRequest.Builder(MyWorker.class)
	.build();
	workManager.enqueue(startServiceRequest);
	}
	}
	package varunon9.me.dynamicwallpaper;

	import android.app.Notification;
	import android.app.NotificationChannel;
	import android.app.NotificationManager;
	import android.app.PendingIntent;
	import android.app.Service;
	import android.content.Intent;
	import android.os.Build;
	import android.os.IBinder;
	import android.util.Log;

	import androidx.core.app.NotificationCompat;

	public class MyService extends Service {
	private String TAG = "MyService";
	public static boolean isServiceRunning;
	private String CHANNEL_ID = "NOTIFICATION_CHANNEL";

	public MyService() {
	Log.d(TAG, "constructor called");
	isServiceRunning = false;
	}

	@Override
	public void onCreate() {
	super.onCreate();
	Log.d(TAG, "onCreate called");
	createNotificationChannel();
	isServiceRunning = true;
	}

	@Override
	public IBinder onBind(Intent intent) {
	return null;
	}

	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
	Log.d(TAG, "onStartCommand called");
	Intent notificationIntent = new Intent(this, MainActivity.class);
	PendingIntent pendingIntent = PendingIntent.getActivity(this,
	0, notificationIntent, 0);
	Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
	.setContentTitle("Service is Running")
	.setContentText("Listening for Screen Off/On events")
	.setSmallIcon(R.drawable.ic_wallpaper_black_24dp)
	.setContentIntent(pendingIntent)
	.setColor(getResources().getColor(R.color.colorPrimary))
	.build();

	startForeground(1, notification);
	return START_STICKY;
	}

	private void createNotificationChannel() {
	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
	String appName = getString(R.string.app_name);
	NotificationChannel serviceChannel = new NotificationChannel(
	CHANNEL_ID,
	appName,
	NotificationManager.IMPORTANCE_DEFAULT
	);
	NotificationManager manager = getSystemService(NotificationManager.class);
	manager.createNotificationChannel(serviceChannel);
	}
	}

	@Override
	public void onDestroy() {
	Log.d(TAG, "onDestroy called");
	isServiceRunning = false;
	stopForeground(true);

	// call MyReceiver which will restart this service via a worker
	Intent broadcastIntent = new Intent(this, MyReceiver.class);
	sendBroadcast(broadcastIntent);

	super.onDestroy();
	}
	}