Creating Login page in Android Studio

In this tutorial, I will tell you how to create an example of simple Login Page in Android Studio which takes a preset user name "user" and password "123456". If the both entries are matched with the correct values, a transition to another activity (say home page) takes place. Otherwise it rejects by creating a Toast message "Invalid Credentials". 

The code snippet for MainActivity.Java is given below: 

package com.learnandroid.loginactivity;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
    EditText loginText, passwordText;
    Button btnLogin;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        loginText = (EditText) findViewById(R.id.login);
        passwordText= (EditText) findViewById(R.id.password);
        btnLogin = (Button) findViewById(R.id.buttonLogin);
        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String username = loginText.getText().toString();
                String password = passwordText.getText().toString();
                if(username.equals("user") && (password.equals("123456")))
                {
                    Toast.makeText(MainActivity.this, "Welcome", Toast.LENGTH_SHORT).show();
                    Intent intent= new Intent(getApplicationContext(),NewActivity.class);
                    startActivity(intent);
                }else
                {
                   Toast.makeText(MainActivity.this, "Invalid Credentials", Toast.LENGTH_SHORT).show();
                }
            } });    

}}

The code snippet for activity_main.xml is given below: 

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <TextView
        android:id="@+id/login_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="User Name"
        android:layout_marginTop="200dp"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:textSize="24dp"
        />

    <EditText
        android:id="@+id/login"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:inputType="textPersonName"
        android:layout_below="@+id/login_text"
        />


    <TextView
        android:id="@+id/password_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Password"
        android:layout_marginTop="50dp"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:textSize="24dp"
        android:layout_below="@+id/login"

        />

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:inputType="textPersonName"
        android:layout_below="@+id/password_text"
        />

    <Button
        android:id="@+id/buttonLogin"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Login"
        android:layout_marginTop="50dp"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:layout_below="@+id/password"
        android:textSize="24dp"
        />
</RelativeLayout>

That's all, run the code...