81.7 Checking the Security Settings

Earlier in this chapter steps were taken to configure the lock screen and register fingerprints on the device or emulator on which the app is going to be tested. It is important, however, to include defensive code in the app to make sure that these requirements have been met before attempting to seek fingerprint authentication. These steps will be performed within the onCreate method residing in the MainActivity.java file, making use of the Keyguard and PackageManager manager services. Note that code has also been added to verify that the USE_BIOMETRIC permission has been configured for the app:

package com.ebookfrenzy.biometricdemo;

 

import androidx.appcompat.app.AppCompatActivity;

import androidx.core.app.ActivityCompat;

 

import android.widget.Toast;

import android.Manifest;

import android.content.pm.PackageManager;

 

import android.app.KeyguardManager;

 

public class MainActivity extends...