MainActivity.java

package com.example.hooman.loginredirect;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
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 username, password;
    Button login_button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        username = (EditText) findViewById(R.id.editText);
        password = (EditText) findViewById(R.id.editText2);
        login_button = (Button) findViewById(R.id.button);
        login_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(username.getText().toString().equals("admin") && password.getText().toString().equals("password")) {
                    Toast.makeText(MainActivity.this, "Login Successful!", Toast.LENGTH_SHORT).show();
                    final Intent i = new Intent(MainActivity.this, LoginSuccess.class);
                    startActivity(i);
                } else {
                    Toast.makeText(MainActivity.this, "Invalid username or password!", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}