I’m facing an issue with triggering a WorkManager worker from the onDestroy method of my MainActivity. Here’s the scenario:

I’ve implemented a ClearCacheWorker using WorkManager to handle background tasks when the app is closed. I’m scheduling this worker in the onDestroy method like this:

@Override
protected void onDestroy() {
    Log.d("MainActivity", "onDestroy called");
    ClearCacheScheduler.scheduleClearCache(this);
    super.onDestroy();
}

The ClearCacheScheduler looks like this:

public class ClearCacheScheduler {
    public static void scheduleClearCache(Context context) {
        Log.d("ClearCacheScheduler", "scheduleClearCache called");
 

        OneTimeWorkRequest request = new OneTimeWorkRequest.Builder(ClearCacheWorker.class)
            
            .setInitialDelay(0, TimeUnit.SECONDS)
            .addTag("clear_cache")
            .build();

        WorkManager.getInstance(context).enqueue(request)
    }
}

However, when I close the app, the onDestroy method gets called (verified with logs), but the ClearCacheWorker’s doWork() is never triggered. Here’s my worker implementation:

public class ClearCacheWorker extends Worker {
    private static final String TAG = "ClearCacheWorker";

    public ClearCacheWorker(@NonNull Context context, @NonNull WorkerParameters workerParams) {
        super(context, workerParams);
    }

    @NonNull
    @Override
    public Result doWork() {
        Log.d(TAG, "doWork()");

        try {
            Thread.sleep(500); // Simulate delay
        } catch (InterruptedException e) {
            Log.d(TAG, "doWork() interrupted");
            return Result.success();
        }

        if (isAppInForeground(getApplicationContext())) {
            Log.d(TAG, "doWork() App is in foreground");
            return Result.success();
        }

        Log.d(TAG, "doWork() App is in background");
        Intent intent = new Intent(getApplicationContext(), ClearCacheService.class);
        intent.putExtras(new android.os.Bundle());
        getApplicationContext().startService(intent);

        return Result.success();
    }

    private boolean isAppInForeground(Context context) {
        android.app.ActivityManager activityManager =
            (android.app.ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        java.util.List<android.app.ActivityManager.RunningAppProcessInfo> processes =
            activityManager.getRunningAppProcesses();
        if (processes != null) {
            for (android.app.ActivityManager.RunningAppProcessInfo processInfo : processes) {
                if (processInfo.importance ==
                        android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND
                    && processInfo.processName.equals(context.getPackageName())) {
                    Log.d(TAG, "doWork() App in foreground");
                    return true;
                }
            }
        }
        Log.d(TAG, "doWork() App in background");
        return false;
    }
}

I’ve checked that:

1. The onDestroy method logs properly when the app is closed.

2. The scheduleClearCache method is being triggered

Questions:

1. Is there a reason why WorkManager doesn’t launch the worker when called from onDestroy?

2. Could it be related to the app’s process being killed before WorkManager can enqueue or execute the work?

3. Would scheduling the worker in onStop or another lifecycle method be more reliable?

Any insights or suggestions would be greatly appreciated!

Thanks in advance for your help!