Android MVP Login Example

1/  Create A New Project .

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:background="@color/black">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <androidx.appcompat.widget.AppCompatEditText
            android:id="@+id/emailEditText"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:hint="user: user@gmail.com"
            android:textColorHint="@color/white"
            android:layout_marginTop="45dp"
            android:padding="20dp"
            android:textColor="@color/white"
            android:layout_marginStart="25dp"
            android:layout_marginEnd="25dp"
            android:inputType="textEmailAddress" />

        <androidx.appcompat.widget.AppCompatEditText
            android:id="@+id/passwordEditText"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginTop="25dp"
            android:hint="password : 123456"
            android:textColorHint="@color/white"
            android:padding="20dp"
            android:textColor="@color/white"
            android:layout_marginStart="25dp"
            android:layout_marginEnd="25dp"
            android:inputType="textPassword" />

        <androidx.appcompat.widget.AppCompatButton
            android:id="@+id/loginButton"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:layout_marginBottom="20dp"
            android:layout_marginTop="20dp"
            android:padding="18dp"
            android:textSize="16sp"
            android:textColor="@color/black"
            android:layout_marginStart="25dp"
            android:layout_marginEnd="25dp"
            android:focusable="true"
            android:text="Signin" />

    </LinearLayout>


</RelativeLayout>

package com.example.mvplogintest;

public interface LoginContract {
    interface View {
        void showInvalidCredentialsError();
        void showLoginSuccessMessage();
    }
    
    interface PresenterData {
        void onLoginButtonClick(String email, String password);
    }

    interface  ModelData{
        boolean  loginInfo(String userInput, String passInput);

    }

  

}


 

package com.example.mvplogintest;

public class UserLoginModel implements LoginContract.ModelData {

    String userName;
    String password;

    public UserLoginModel(String userName, String password) {
        this.userName = userName;
        this.password = password;
    }

    @Override
    public boolean loginInfo(String userInput, String passInput) {

        if (userName.equals(userInput) && password.equals(passInput)){
            return true;
        }else {
            return false;
        }
    }



}

package com.example.mvplogintest;



public class LoginPresenter implements LoginContract.PresenterData {

    private LoginContract.View viewIterface;

    private LoginContract.ModelData model;
    String user;
    String pass;
    public LoginPresenter(LoginContract.View view,String user,String pass) {
        viewIterface = view;
        this.user = user;
        this.pass = pass;

        model=new UserLoginModel(user,pass);
    }

    @Override
    public void onLoginButtonClick(String userInput, String passInput) {
        if (model.loginInfo(userInput,passInput)) {
            viewIterface.showLoginSuccessMessage();
        } else {
            viewIterface.showInvalidCredentialsError();
        }
    }
}

 

package com.example.mvplogintest;

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

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity implements LoginContract.View{


    private EditText etEmail;
    private EditText etPassword;
    private Button btnSigin;
    private LoginPresenter loginPresenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);

        etEmail = findViewById(R.id.emailEditText);
        etPassword = findViewById(R.id.passwordEditText);
        btnSigin = findViewById(R.id.loginButton);
        loginPresenter = new LoginPresenter(this,"user@gmail.com","123456");

        btnSigin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String email = etEmail.getText().toString().trim();
                String password = etPassword.getText().toString().trim();

                loginPresenter.onLoginButtonClick(email, password);
            }
        });


    }

    @Override
    public void showInvalidCredentialsError() {
        Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void showLoginSuccessMessage() {
        Toast.makeText(this, "Success", Toast.LENGTH_SHORT).show();
    }
}

Run code then see output.