MainActivity2.java

package com.example.myapplication;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.biometric.BiometricManager;
import androidx.biometric.BiometricPrompt;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.core.content.ContextCompat;

import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import java.util.concurrent.Executor;

public class MainActivity2 extends AppCompatActivity {

    BiometricPrompt biometricPrompt;
    ConstraintLayout mMainLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        mMainLayout = findViewById(R.id.main_layout);

        BiometricManager biometricManager = BiometricManager.from(this);




        switch (biometricManager.canAuthenticate()) {


            case BiometricManager.BIOMETRIC_ERROR_NO_HARDWARE:
                Toast.makeText(getApplicationContext(), "Device doesn't have fingerprint service", Toast.LENGTH_SHORT).show();
                break;

            case BiometricManager.BIOMETRIC_ERROR_HW_UNAVAILABLE:
                Toast.makeText(getApplicationContext(), "Currently fingerprint sensor not working", Toast.LENGTH_SHORT).show();
                break;

            case BiometricManager.BIOMETRIC_ERROR_NONE_ENROLLED:
                Toast.makeText(getApplicationContext(), "No fingerprint assigned", Toast.LENGTH_SHORT).show();
                break;

            case BiometricManager.BIOMETRIC_ERROR_SECURITY_UPDATE_REQUIRED:

            case BiometricManager.BIOMETRIC_ERROR_UNSUPPORTED:

            case BiometricManager.BIOMETRIC_STATUS_UNKNOWN:

            case BiometricManager.BIOMETRIC_SUCCESS:
                break;
        }

        Executor executor = ContextCompat.getMainExecutor(this);

        biometricPrompt = new BiometricPrompt(MainActivity2.this, executor, new BiometricPrompt.AuthenticationCallback() {
            @Override
            public void onAuthenticationError(int errorCode, @NonNull CharSequence errString) {
                super.onAuthenticationError(errorCode, errString);
            }

            @Override
            public void onAuthenticationSucceeded(@NonNull BiometricPrompt.AuthenticationResult result) {
                super.onAuthenticationSucceeded(result);
                Toast.makeText(getApplicationContext(), "login success", Toast.LENGTH_SHORT).show();
                mMainLayout.setVisibility(View.VISIBLE);
            }

            @Override
            public void onAuthenticationFailed() {
                super.onAuthenticationFailed();
            }
        });

        BiometricPrompt.PromptInfo promptInfo = new BiometricPrompt.PromptInfo.Builder().setTitle("Attendance")
                .setDescription("Use fingerprint to Login").setNegativeButtonText("cancel").build();

        biometricPrompt.authenticate(promptInfo);



    }
}