android-background-execution

Android Background Execution Skill

This skill provides a structured approach to implementing background work in Android, ensuring high performance, battery efficiency, and compliance with modern system restrictions (API 30 and above).

When to Use

• Implementing deferred tasks (e.g., database sync, log uploading).
• Running immediate, user-perceivable tasks (e.g., media playback, active navigation).
• Scheduling time-sensitive actions (e.g., calendar reminders, exact alarms).
• Navigating background execution limits and battery optimization (Doze Mode).

🛠 Core Technologies

1. WorkManager (Recommended)

Use for persistent, deferrable work that must execute even if the app exits or the device restarts.

• Immediate: Tasks that should start as soon as possible (can use setExpedited(true)).
• Long-Running: Tasks that might run longer than 10 minutes (API 31+ requires a Foreground Service).
• Periodic: Recurring tasks (minimum 15-minute interval).

2. Foreground Services

Use for immediate, user-visible work that is the primary focus of the app (e.g., Music Player, Step Tracker).

• Must show a persistent notification.
• From API 34+, you must declare a foregroundServiceType in the manifest.

3. Alarms (AlarmManager)

Use for exact, time-based scheduling.

• Avoid for general background work to save battery.
• setExactAndAllowWhileIdle() is for high-precision needs (e.g., clocks).

🚀 Implementation Workflow

1. Choose the Right Tool

2. Implementation Patterns

WorkManager (Kotlin)

class SyncWorker(context: Context, params: WorkerParameters) : CoroutineWorker(context, params) {
    override suspend fun doWork(): Result {
        return try {
            // Background logic here
            Result.success()
        } catch (e: Exception) {
            if (runAttemptCount < 3) Result.retry() else Result.failure()
        }
    }
}

// Enqueueing

val constraints = Constraints.Builder()
    .setRequiredNetworkType(NetworkType.CONNECTED)
    .setRequiresBatteryNotLow(true)
    .build()

val syncRequest = OneTimeWorkRequestBuilder<SyncWorker>()
    .setConstraints(constraints)
    .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 1, TimeUnit.MINUTES)
    .build()

WorkManager.getInstance(context).enqueue(syncRequest)

Foreground Service (API 34+)

1. Manifest Declaration:

<service
    android:name=".MyService"
    android:foregroundServiceType="dataSync" />

1. Service Implementation:

class MyService : Service() {
    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        val notification = NotificationCompat.Builder(this, CHANNEL_ID)
            .setContentTitle("Syncing Data")
            .setSmallIcon(R.drawable.ic_sync)
            .build()
        
        ServiceCompat.startForeground(this, 1, notification, FOREGROUND_SERVICE_TYPE_DATA_SYNC)
        // logic...
        return START_NOT_STICKY
    }
}

💡 Best Practices & Constraints

• Battery Optimization: Respect Doze Mode. WorkManager handles this automatically by batching requests.
• Expedited Work: For WorkManager tasks that need to start immediately, use setExpedited(true). Note that this has quotas.
• Connectivity: Always use Constraints in WorkManager to prevent unnecessary wakeups when offline.
• Error Handling: Implement exponential backoff for retries to avoid "looping" failures.
• Testing: Use WorkManagerTestInitHelper for testing workers in unit/integration tests without waiting for real-world constraints.

📂 Project Organization

• Place Workers in com.example.app.data.worker or com.example.app.ui.background.
• Place Services in com.example.app.service.
• Keep business logic in Repository classes, not inside Worker or Service classes.