permissions - Why android API:getNotificationPolicy can't run successfully on some emulator with specific sdk version?

Question

The Unit Test code is attached:

    import android.app.NotificationManager;
    import android.app.NotificationManager.Policy;
    import android.content.Context;
    import androidx.test.InstrumentationRegistry;
    import androidx.test.runner.AndroidJUnit4;
    import org.junit.Test;
    import org.junit.runner.RunWith;

    @RunWith(AndroidJUnit4.class)
    public class TestCase_com_cabooze_buzzoff__1592700345 {
      @Test
      public void testCase() throws Exception {
         Context var1 = InstrumentationRegistry.getTargetContext();
         Object var2 = var1.getSystemService("notification");
         NotificationManager var3 = (NotificationManager)var2;
         Policy var4 = var3.getNotificationPolicy();
      }
    }

I run the above code on sdk 21-29 and the results are :

21-22：NoSuchMethodError

23-27：SecurityException

28-29：success

The minSDKVersion of my apk is 21; targetSDKVersion is 30.

I am wondering why getNotificationPolicy will throw SecurityException on 23-27, considering the google doc yield that getNotificationPolicy need android.permission.ACCESS_NOTIFICATION_POLICY which is a normal permission. Besides, why it can run successfully on 28-29.

question from:https://stackoverflow.com/questions/65648936/why-android-apigetnotificationpolicy-cant-run-successfully-on-some-emulator-wi

Answer 1

Waitting for answers