bank.java

java语言与面向对象程序设计源程序

import java.awt.*;
import java.awt.event.*;

 public class Bank extends Frame implements ActionListener
{  protected final static int NUM_ACCOUNTS = 8;
   private   final static int WASTE_TIME   = 1;
   private int      accounts[] = new int[NUM_ACCOUNTS];
   private Customer customer[] = new Customer[NUM_ACCOUNTS];
   private int      counter    = 0;

private Label    status     = new Label("Transfers Completed: 0");
private TextArea display    = new TextArea();
private Button   show       = new Button("Show Accounts");
private Button   start      = new Button("Restart");
private Button   stop       = new Button("Stop");


   public Bank()
{  super("Mystery Money");
   Panel buttons = new Panel(); buttons.setLayout(new FlowLayout());
   buttons.add(show);  show.addActionListener(this);
   buttons.add(start); start.addActionListener(this);
   buttons.add(stop);  stop.addActionListener(this);
   setLayout(new BorderLayout());
   add("North", status); add("South",  buttons); add("Center", display);
   for (int i = 0; i < accounts.length; i++)
      accounts[i] = 100000;
   start();
   validate(); setSize(300, 300); setVisible(true);
   addWindowListener(new WindowAdapter()
        { public void windowClosing(WindowEvent we)
          {  System.exit(0); }
        });
}

 
   public void transfer(int from, int into, int amount)
   {  if ((accounts[from] >= amount) && (from != into))
      {  int newAmountFrom = accounts[from] - amount;
         int newAmountTo   = accounts[into] + amount;
         wasteSomeTime();
         accounts[from] = newAmountFrom;
         accounts[into] = newAmountTo;
      }
    status.setText("Transfers completed: " + counter++);
   }
   private void start()
   {  stop();
      for (int i = 0; i < accounts.length; i++)
         customer[i] = new Customer(i, this);
   }
   private void stop()
   {  for (int i = 0; i < accounts.length; i++)
         if (customer[i] != null)
            customer[i].halt();
   }
   private void wasteSomeTime()
   {  try
      {  Thread.sleep(WASTE_TIME); }
      catch(InterruptedException ie)
      {  System.err.println("Error: " + ie); }
   }
private void showAccounts()
{  int sum = 0;
   for (int i = 0; i < accounts.length; i++)
   {  sum += accounts[i];
      display.append("\nAccount " + i + ": $" + accounts[i]);
   }
   display.append("\nTotal Amount:    $" + sum);
   display.append("\nTotal Transfers: " + counter + "\n");
}
  public void actionPerformed(ActionEvent ae)
   {  if (ae.getSource() == show)
         showAccounts();
      else if (ae.getSource() == start)
         start();
      else if (ae.getSource() == stop)
         stop();
   }

   public static void main(String args[])
   {  Bank bank = new Bank(); }




}