Ekrandaki uygulamayı çalıştıran Java kodu aşağıda. Oldukça basit, butona basınca submitOrder fonksiyonunu çağırıyor. submitOrder'da diğer 2 fonksiyonu tetikliyor.

package com.example.ersanaskin.justjava;
/** * Add your package below. Package name can be found in the project's AndroidManifest.xml file. 

* This is the package name our example uses: * * package com.example.android.justjava; */

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.view.View;

import android.widget.TextView;

import java.text.NumberFormat;

/** * This app displays an order form to order coffee. */

public class MainActivity extends AppCompatActivity {

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    /**     * This method is called when the order button is clicked.     */

        public void submitOrder(View view) {
        display(2 * 2);

        displayPrice(2 * 5);

        }

    /**     * This method displays the given quantity value on the screen.     */

    private void display(int number) {
        TextView quantityTextView = (TextView) findViewById(R.id.quantity_text_view);

        quantityTextView.setText("" + number);

    }

    private void displayPrice(int number) {
        TextView priceTextView = (TextView) findViewById(R.id.price_text_view);

        priceTextView.setText(NumberFormat.getCurrencyInstance().format(number));

    }