MainActivity.java

package com.example.root.first;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    void login(View view){
        EditText loginText = (EditText)findViewById(R.id.loginText);
        String username = loginText.getText().toString();
        EditText passwordText = (EditText)findViewById(R.id.passwordText);
        String password = passwordText.getText().toString();
        if(username.equals("Admin") && (password.equals("1234"))) {
            Intent intent = new Intent(this, loggedInActivity.class);
            intent.putExtra("username", username);
            startActivity(intent);
        }
    }
}