Airline Reservation System with boolean Array

Question

Good morning,
I have written the following code for an airline reservation system. The applet will assign the user a seat in either economy or first class. When first class is full, it will offer economy seats. This works - but when it is about to assign the last seat in 'economy', the program stops working. The error messages suggest a problem in the method call to selectSeat() in the 'economy' part of the code. I can't see the problem, though, as this code is identical to the code I used for the 'first class' part.
//Airline booking
//Coded by Eoghain on 16/9/07
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class AirlineApplet extends JApplet implements ActionListener {
     JButton printPass;
     JTextArea outputArea;
     String output;
     int seatType, seatNum, choice;
     boolean[] seatArray = {false, false, false, false, false, false, false, false, false, false};
     public void init() {
          Container container = getContentPane();
          container.setLayout(new FlowLayout());
          chooseType();
          printPass = new JButton ("Click to print boarding pass");
          printPass.addActionListener(this);
          outputArea = new JTextArea(40, 40);
          container.add(printPass);
          container.add(outputArea);
     public void chooseType() {
          seatType = Integer.parseInt(JOptionPane.showInputDialog("Please type 1 first First Class or 2 for Economy"));
          selectSeat(seatType);
     public void actionPerformed(ActionEvent event) {
          outputArea.append(output);
          chooseType();
     public void selectSeat(int x) {
          //argument selects between first and economy
          if (x == 1)
               if (seatArray[0] && seatArray[1] && seatArray[2] && seatArray[3] && seatArray[4])
                    choice = Integer.parseInt(JOptionPane.showInputDialog("There are no seats available in First Class. Would you like Economy? 1 for Yes, 2 for No."));
                    if (choice == 1)
                         selectSeat(2);
                    else
                         JOptionPane.showMessageDialog(null, "Next flight leaves in 3 hours.");
               else
               //do first stuff and make sure the seat is unoccupied
               seatNum = (int)(Math.random()*5);
                    if (!seatArray[seatNum])
                         seatArray[seatNum] = true;
                    else
                         selectSeat(x);
               output = "Your have seat " + seatNum + " in First Class. \n";
          else
               if (seatArray[5] && seatArray[6] && seatArray[7] && seatArray[8] && seatArray[9])
                    JOptionPane.showMessageDialog(null, "There are no seats available in Economy. Sorry.");
               else
               //do economy stuff
               seatNum = (5 + (int)(Math.random()*4));
                    if (!seatArray[seatNum])
                         seatArray[seatNum] = true;
                    else
                         selectSeat(x);
               output = "Your have seat " + seatNum + " in Economy. \n";
}Any advice would be greatly appreciated,
-Eoghain

Answer 1

You've created a nice little infinite loop in selectSeat here:
    if (!seatArray[seatNum])
        seatArray[seatNum] = true;
    else
        selectSeat(x);If you run out of 2nd class seats, your program isn't told to stop, it's told to just keep looking and looking and looking and looking and looking and looking and looking and looking and looking ...
and so on. Don't do this.