business.java

java编程开发技巧与实例的编译测试通过的所有例程

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

public abstract class Business extends Panel implements Runnable
{
	protected Agent[] agent			=	new Agent[Simulator.NUM_AGENTS];
	protected Label[] labelAgent	=	new Label[Simulator.NUM_AGENTS];
	protected Label labelQueue		=	new Label("Customers waiting: 0");
	protected Label labelServed		=	new Label("Customers waiting: 0");
	protected Label labelWait		=	new Label("Average wait: 0");
	protected int numAgents			=	Simulator.NUM_INITIAL_AGENTS;
	protected int numCustomer		=	0;
	protected long totalWait		=	0L;
	private Thread thread			=	null;
	private boolean doorIsOpen		=	false;
	public Business(String title)
	{
		super();
		setup(title);
	}
	public abstract void generateCustomer();
	public abstract Customer requestCustomerFor(int ID);
	public abstract void updateDisplay();
	public void checkoutCustomer(int handled, long waitTime)
	{
		numCustomer ++;
		totalWait += waitTime;
	}
	public void addAgent()
	{
		if (numAgents < Simulator.NUM_AGENTS)
		{
			agent[numAgents]	=	new Agent(this, numAgents);
			agent[numAgents].start();
			numAgents ++;
		}
	}
	public void retireAgent()
	{
		if (numAgents > 1)
		{
			agent[numAgents - 1].halt();
			numAgents --;
		}
	}
	public void start()
	{
		if (thread == null)
		{
			thread		=	new Thread(this);
			doorIsOpen	=	true;
			thread.start();
			for	(int i = 0; i < numAgents; i ++)
				agent[i].start();
		}
	}
	public void stop()
	{
		doorIsOpen	=	false;
		thread	=	null;
		for	(int i = 0; i < numAgents; i ++)
			agent[i].halt();
	}
	public void openDoor()
	{
		doorIsOpen	=	true;
	}
	public void closeDoor()
	{
		doorIsOpen	=	false;
	}
	public void run()
	{
		while	(thread == Thread.currentThread())
		{
			try
			{
				thread.sleep((int)(Math.random() * Simulator.MAX_NO_CUSTOMERS));
				if (doorIsOpen)
					generateCustomer();
				updateDisplay();
			}
			catch	(InterruptedException ie)
			{
				System.out.println("business exception: " + ie);
			}
		}
	}
	private void setup(String title)
	{
		Panel agentPanel	=	new Panel();
		agentPanel.setLayout(new GridLayout(Simulator.NUM_AGENTS + 3, 1));
		for (int i = 0; i < Simulator.NUM_AGENTS; i ++)
		{
			labelAgent[i]	=	new Label("agent " + i + "served: 0");
			agentPanel.add(labelAgent[i]);
			agent[i]		=	new Agent(this, i);
		}
		for (int i = numAgents; i < Simulator.NUM_AGENTS; i ++)
			labelAgent[i].setText("Agent " + i + ": inactive");
		agentPanel.add(labelQueue);
		agentPanel.add(labelServed);
		agentPanel.add(labelWait);
		setLayout(new BorderLayout());
		add("Center", agentPanel);
		add("North", new Label(title));
	}
}