Two number sum in Android Studio (JAVA)

 package com.example.twonumbercalculate;

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.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    EditText n1 , n2;
    TextView textView;
    Button button2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = findViewById(R.id.textView);
        button2 = findViewById(R.id.button2);
        n1 = findViewById(R.id.n1);
        n2 = findViewById(R.id.n2);

        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int sum = Integer.parseInt(n1.getText().toString()) + Integer.parseInt(n2.getText().toString());
                
                textView.setText("This Two number sum is  " + sum);
                Toast.makeText(MainActivity.this, "Calculate completed", Toast.LENGTH_SHORT).show();
            }
        });

    }
}