为什么广播接收器不适用于服务应用程序android？

Question

I have a project which is only a service and it has no activity and user interface. I want to start my application background service when phone boot completely. but I never receive the "BOOT_COMPLETED" Message from OS. these are my code:

Manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.droid.arghaman.location_tracker">

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

    <receiver android:name=".BootBroadcastReceiver"
    android:enabled="true"
    android:exported="false"
    android:label="StartServiceAtBootReceiver">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
        <category android:name="android.intent.category.DEFAULT"></category>
    </intent-filter>

    </receiver>
</application>

<service android:name=".mySevice"></service>
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"></uses-permission>
</manifest>

Broadcast Receiver:

public class BootBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Log.i("boot Received", intent.getAction());
        Intent serviceLuncher = new Intent(context, myService.class);
        context.startService(serviceLuncher);
    }
}

myService:

public class LocationNotifierService extends Service {
   Timer timer ;
   @Nullable
   @Override
   public IBinder onBind(Intent intent) {
       return null;
   }

   @Override
   public void onCreate(){
       timer = new Timer();
       timer.schedule(new TimerTask() {
       @Override
       public void run() {

 Toast.makeText(getBaseContext(),"Location",Toast.LENGTH_SHORT).show();
          }
          },3000);
      }

    @Override
    public void onDestroy(){

    }
    @Override
    public int onStartCommand(Intent intent, int flagId, int startId){
        return START_STICKY;
    }
}

but I never get "boot Received" log. is there any mistake and is there any way to debug my program?

I Recommend that my project must have only this Service and it cannot have any UI.

Answer 1

I never receive the "BOOT_COMPLETED" Message from OS

Partly, that is because you do not have a <receiver> set up to receive android.intent.action.BOOT_COMPLETED broadcasts.

Partly, that is because your app will not receive broadcasts until something on the device uses an explicit Intent to start one of your components. The way your app is set up — without an activity that the user can run — it is unlikely that any app will do this, and so your code will never run.

Also, please bear in mind that Android O has changes designed specifically to prevent background services from running for very long and to limit your ability to get background location updates (which your location_tracker name suggests that you want to add in the future). You may wish to reconsider whether writing this app the way that you are is a wise course.

Answer 2

try this in your manifest

 <receiver android:name=".BootBroadcastReceiver"
    android:enabled="true"
    android:exported="false"
    android:label="StartServiceAtBootReceiver">
      <intent-filter>
         <action android:name="android.intent.action.BOOT_COMPLETED" />
       </intent-filter>
    </receiver>