Firebase Authentication

import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

public class LoginActivity extends AppCompatActivity {
    private EditText edLogin, edPassword;
    private FirebaseAuth mAuth;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login_layout);
        init();

    }

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseUser cUser = mAuth.getCurrentUser();
        if(cUser != null)
        {
            Toast.makeText(this, "User not null", Toast.LENGTH_SHORT).show();
        }
        else
        {
            Toast.makeText(this, "User null", Toast.LENGTH_SHORT).show();
        }
    }

    private void init()
    {
        edLogin = findViewById(R.id.edLogin);
        edPassword = findViewById(R.id.edPassword);
        mAuth = FirebaseAuth.getInstance();
    }
    public void onClickSignUp(View view)
    {
        if(!TextUtils.isEmpty(edLogin.getText().toString()) && !TextUtils.isEmpty(edPassword.getText().toString()))
        {
      mAuth.createUserWithEmailAndPassword(edLogin.getText().toString(),edPassword.getText().toString()).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
          @Override
          public void onComplete(@NonNull Task<AuthResult> task) {
              if(task.isSuccessful())
              {
                  Toast.makeText(getApplicationContext(), "User SignUp Successful", Toast.LENGTH_SHORT).show();
              }
              else
              {
                  Toast.makeText(getApplicationContext(), "User SignUp failed", Toast.LENGTH_SHORT).show();
              }
          }
      });

        }
        else
        {
            Toast.makeText(getApplicationContext(), "Please entre Email and Password", Toast.LENGTH_SHORT).show();
        }
    }
    public void onClickSignIn(View view)
    {
        if(!TextUtils.isEmpty(edLogin.getText().toString()) && !TextUtils.isEmpty(edPassword.getText().toString())){
    mAuth.signInWithEmailAndPassword(edLogin.getText().toString(),edPassword.getText().toString()).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {
            if(task.isSuccessful())
            {
                Toast.makeText(getApplicationContext(), "User SignIn Successful", Toast.LENGTH_SHORT).show();
            }
            else
            {
                Toast.makeText(getApplicationContext(), "User SignIn failed", Toast.LENGTH_SHORT).show();
            }
        }
    });
        }
    }
}