import java.awt.event.*;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.*;

/**
*
* @author
*/
public class ShopTester extends JFrame implements ActionListener {

public static void main(String[] args) {
   ShopTester shopTester = new ShopTester();
}

private final String[] items = {
   "Save", "Exit"
};
private final int SAVE_INDEX = 0;
private final int EXIT_INDEX = 1;

private JMenu menu;
private JMenuItem[] menuItem;
private JMenuBar menuBar;
private JPanel panel;
private JTextArea jTextArea;
private JButton[] buttons;

public ShopTester() {
   super();
   setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

   menu = new JMenu("File");
   menuItem = new JMenuItem[items.length];
   menuBar = new JMenuBar();
   for (int i = 0; i < menuItem.length; i++) {
         menuItem[i] = new JMenuItem(items[i]);
         menuItem[i].addActionListener(this);
         menu.add(menuItem[i]);
   }
   menuBar.add(menu);
   setJMenuBar(menuBar);
   buttons = new JButton[2];

   add(setupPanel());
   pack();
   setVisible(true);
}

private static String testCase1() {
   ShopOrder order = new ShopOrder();
   return order.getOrderDetails();
}

private static String testCase2() {
   ShopOrder order = new ShopOrder("Coffee", 5);
   return order.getOrderDetails();
}

private static String testCase3() {
   ShopOrder order = new ShopOrder("Coffee", 6, 50);
   return order.getOrderDetails();
}

private static String testCase4() {
   ShopOrder order = new ShopOrder("Coffee", 20, 50);
   return order.getOrderDetails();
}

private static String testCase5() {
   ShopOrder order = new ShopOrder("Muffin", 4, 8);
   return order.getOrderDetails();
}

private static String testCase6() {
   ShopOrder order = new InternalOrder("Tomato", 7);
   return order.getOrderDetails();
}

private static String testCase7() {
   ShopOrder order = new InternalOrder("Bread", 7);
   return order.getOrderDetails();
}

private static String testCase8() {
   ShopOrder order = new ShopOrder("Coffee", 20, -50);
   return order.getOrderDetails();
}

private static String testCase9() {
   ShopOrder order = new ShopOrder("Toast", 2);
   return order.getOrderDetails();
}

private static String testCase10() {
   ShopOrder order = new ShopOrder("Honey", 2);
   return order.getOrderDetails();
}

private void testing() {
   String text = "";
   text += getBetterResult(testCase1());
   text += getBetterResult(testCase2());
   text += getBetterResult(testCase3());
   text += getBetterResult(testCase4());
   text += getBetterResult(testCase5());
   text += getBetterResult(testCase6());
   text += getBetterResult(testCase7());
   text += getBetterResult(testCase8());
   text += getBetterResult(testCase9());
   text += getBetterResult(testCase10());
   jTextArea.setText(text);
}

private String getBetterResult(String result){
   return "Test case: " + ShopOrder.getOrderNum()
            + System.lineSeparator() + System.lineSeparator()
            + result
            + System.lineSeparator()
            + System.lineSeparator()
            + "------------------------------------------------------------"
            + System.lineSeparator()
            + System.lineSeparator();
}

@Override
public void actionPerformed(ActionEvent e) {
   Object source = e.getSource();
   if (source == buttons[1]
            || source == menuItem[EXIT_INDEX]) {
         System.exit(0);
   } else if (source == buttons[0]) {
         testing();
   } else if (source == menuItem[SAVE_INDEX]) {
         JFileChooser fileChooser = new JFileChooser();
         int result = fileChooser.showOpenDialog(this);
         if (result == JFileChooser.APPROVE_OPTION) {
            File selectedFile = fileChooser.getSelectedFile();
            try {
               FileWriter fw = new FileWriter(selectedFile);
               fw.write(jTextArea.getText());
               fw.close();
            } catch (IOException ex) {
               JOptionPane.showMessageDialog(null, ex.getMessage());
            }
         }
   }
}

/**
* setup the GUI
*/
private JPanel setupPanel() {
   JPanel jPanel1 = new JPanel();
   JButton jButton3 = new JButton();
   JScrollPane jScrollPane2 = new JScrollPane();
   jTextArea = new JTextArea();
   JButton jButton4 = new JButton();

   buttons[0] = jButton3;
   buttons[1] = jButton4;

   setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

   jButton3.setText("Run Tests");
   jButton3.addActionListener(this);
   jButton4.addActionListener(this);

   jTextArea.setColumns(20);
   jTextArea.setRows(5);
   jScrollPane2.setViewportView(jTextArea);

   jButton4.setText("Exit");

   GroupLayout jPanel1Layout = new GroupLayout(jPanel1);
   jPanel1.setLayout(jPanel1Layout);
   jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                     .addGroup(jPanel1Layout.createSequentialGroup()
                           .addGap(29, 29, 29)
                           .addGroup(jPanel1Layout.createParallelGroup(GroupLayout.Alignment.TRAILING)
                                    .addComponent(jButton4)
                                    .addGroup(jPanel1Layout.createSequentialGroup()
                                             .addComponent(jButton3)
                                             .addGap(39, 39, 39)
                                             .addComponent(jScrollPane2, GroupLayout.PREFERRED_SIZE, 401, GroupLayout.PREFERRED_SIZE)))
                           .addContainerGap(29, Short.MAX_VALUE))
   );
   jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                     .addGroup(jPanel1Layout.createSequentialGroup()
                           .addGroup(jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                                    .addGroup(jPanel1Layout.createSequentialGroup()
                                             .addGap(43, 43, 43)
                                             .addComponent(jButton3))
                                    .addGroup(jPanel1Layout.createSequentialGroup()
                                             .addContainerGap()
                                             .addComponent(jScrollPane2, GroupLayout.PREFERRED_SIZE, 312, GroupLayout.PREFERRED_SIZE)))
                           .addGap(18, 18, 18)
                           .addComponent(jButton4)
                           .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
   );
   return jPanel1;
}
}

Write a program that will deal with the following scenario. A lectu...