[FIXED] Android background service not starting

Issue

I have read multiple threads on this issue but none of them solved my problem, so I gave up and decided to write this.

I have a service (right now it's a background service but I am going to turn it into a foreground service) which monitors the battery level so it can notify the user when it reaches a certain percentage.

abstract class MonitoringService : Service() {
    private var maxPercentage: Int = -1
    private var thread: Thread? = null
    private lateinit var batteryManager: BatteryManager

    override fun onBind(intent: Intent?): IBinder? {
        return null
    }

    override fun onCreate() {
        batteryManager = getSystemService(BATTERY_SERVICE) as BatteryManager
        Log.d(null, "created service")
    }

    override fun onDestroy() {
        thread?.interrupt()
        updateServiceState(false)
        Log.d(null, "destroyed service")
    }

    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        println("started service")
        if (intent == null) {
            stopSelf(startId)
            updateServiceState(false)
            report(applicationContext, "service started with intent null")

            return START_NOT_STICKY
        }

        when (intent.action) {
            ACTION_START_SERVICE -> {
                // if a thread is already active interrupt it
                thread?.interrupt()

                if (updateMaxPercentage(intent, startId) == 1) return START_NOT_STICKY

                thread = Thread(Runnable {
                    while (true) {
                        if (batteryManager.isCharging && batteryManager.getIntProperty(
                                BatteryManager.BATTERY_PROPERTY_CAPACITY
                            ) == maxPercentage
                        ) {
                            Log.d(null, "time to do it")
                        }
                        Log.d(null, "time to not do it")

                        try {
                            // sleep for 1 minute
                            Thread.sleep(60000)
                        } catch (exception: InterruptedException) {
                            stopSelf(startId)
                            updateServiceState(false)
                            return@Runnable
                        }
                    }
                })
                thread?.start()

                updateServiceState(true)
            }
            ACTION_STOP_SERVICE -> {
                thread?.interrupt()
                stopSelf(startId)
                updateServiceState(false)

                return START_NOT_STICKY
            }
            ACTION_UPDATE_SERVICE -> if (updateMaxPercentage(intent, startId) == 1) return START_NOT_STICKY
            else -> {
                stopSelf(startId)
                updateServiceState(false)
                report(applicationContext, "service started with action null")

                return START_NOT_STICKY
            }
        }

        return START_REDELIVER_INTENT
    }
}

I start the service like so from my activity

    private fun start() {
        val serviceIntent = Intent(applicationContext, MonitoringService::class.java)
        serviceIntent.action = ACTION_START_SERVICE
        serviceIntent.putExtra("maxPercentage", maxPercentage)

        println(startService(intent))
        Log.d(null, "startService")
    }

This is my AndroidManifest.xml

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

    <application
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:theme="@style/Theme.Batconv"
        tools:targetApi="31">

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

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

    </application>
</manifest>

I am testing this on an Android 11 device. The logs show no errors but the service doesn't start.

Thanks.

Solution

Remove the abstract keyword from your MonitoringService declaration:

class MonitoringService : Service()

By declaring it abstract, you are saying that nothing can create an instance of that class.

Answered By - CommonsWare
Answer Checked By - Robin (JavaFixing Admin)