簡單實現多線程同步示例（模擬購票系統）

      以下內容爲實現多線程同步過程，模擬購票系統進行同步購買情況；該處並未考慮線程守護問題，後期將對線程鎖等安全問題進行初步研究！

1、class：Main2

package cn.com.chysoft.demo2;
/**
  * 多線程模擬購票系統
  * 
  * @author chenyong QQ:369232566
  * @date 2013-03-21 下午14:10
  */
  public class main2 {

  /**
  * 多線程共享
  * 
  *@param args
  */
  public static void main(String[] args)   {
// TODO Auto-generated method stb
TicketCentre centre = new TicketCen  tre(10);// 初始化票務中心的票數

Instance instance1 = new Instance(200000, new Ticket(1, "張三", centre));
Instance instance2 = new Instance(800000, new Ticket(2, "王八", centre));
Instance instance3 = new Instance(400000, new Ticket(3, "狗子", centre));
Instance instance4 = new Instance(500000, new Ticket(1, "學妹", centre));
Instance instance5 = new Instance(300000, new Ticket(3, "李五哥", centre));
Instance instance6 = new Instance(100000, new Ticket(1, "習哥", centre));

Thread t1 = new Thread(instance1, "南站（1號窗口）");
Thread t2 = new Thread(instance2, "客運中心（2A號窗口）");
Thread t3 = new Thread(instance3, "南站（2號窗口）");
Thread t4 = new Thread(instance4, "南站（2號窗口）");
Thread t5 = new Thread(instance5, "南站（1號窗口）");
Thread t6 = new Thread(instance6, "客運中心（1B號窗口）");


t1.start();
t2.start();
t3.start();
t4.start();
t5.start();
t6.start();
}
}

//====================================================================================================================

2、多線程實現類 Instance 

package cn.com.chysoft.demo2;

import java.text.SimpleDateFormat;

/**
 * 線程實現
 * 
 * @author chenyong QQ:369232566
 * @date 2013-03-21 下午14:14
 */
public class Instance implements Runnable {
	private Ticket ticket;
	private boolean isOk;// 是否購票成功
	private TicketCentre centre;// 票務中心
	private int wtime;// 購票耗時

	public Instance(int wtime, Ticket ticket) {
		this.wtime = wtime;
		this.ticket = ticket;
	}

	private final void fun(int wtime) {
		this.centre = ticket.getCentre();
		try {
			this.isOk = this.centre.buy(this.ticket);// 購買
			/**
			 * 設置餘票，因爲對象中的數值是共享的
			 */
			this.showMessage(this.ticket.getCentre().getSurplus());
			Thread.sleep(wtime);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	public void showMessage(int current) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss:SSSSSSS --> ");
		StringBuffer sbCtx = new StringBuffer(sdf.format(this.ticket.getTime().getTime()));
		sbCtx.append(this.ticket.getUser());
		if (this.isOk) {
			sbCtx.append(" 在 ").append(Thread.currentThread().getName()).append(" 購買 ").append(this.ticket.getNum()).append(" 張票, 當前剩餘 ").append(current).append(" 張。");
		} else {
			sbCtx.append(" 在 ").append(Thread.currentThread().getName()).append(" 購買失敗！").append("剩餘 ").append(current).append(" 張。");
		}
		System.out.println(sbCtx);
	}

	public void run() {
		this.fun(this.wtime);
	}

}

//====================================================================================================================

3、車票基本信息

package cn.com.chysoft.demo2;

import java.util.Date;

/**
 * 購票信息
 * 
 * @author chenyong QQ:369232566
 * @date 2013-03-21 下午14:14
 */
public class Ticket {
	private String user;// 購買人
	private int num;// 購票數量
	private Date time;// 購票時間
	private TicketCentre centre;// 購票中心

	/**
	 * 初始化車票信息
	 * 
	 * @param num
	 * @param user
	 * @param centre
	 */
	public Ticket(int num, String user, TicketCentre centre) {
		this.num = num;
		this.user = user;
		this.centre = centre;
	}

	public String getUser() {
		return user;
	}

	public void setUser(String user) {
		this.user = user;
	}

	public int getNum() {
		return num;
	}

	public void setNum(int num) {
		this.num = num;
	}

	public void setTime(Date time) {
		this.time = time;
	}

	public Date getTime() {
		return time;
	}

	public TicketCentre getCentre() {
		return centre;
	}

	public void setCentre(TicketCentre centre) {
		this.centre = centre;
	}
}

//====================================================================================================================

4、票務中心處理

package cn.com.chysoft.demo2;

import java.util.Date;

/**
 * 購票中心
 * 
 * @author chenyong QQ:369232566
 * @date 2013-03-21 下午14:01
 */
public class TicketCentre {
	private int tatol = 0;// 車站票數
	private int current = 0;// 當前剩餘票數
	private boolean flag = false;// 是否購完

	/**
	 * 初始化總票值
	 * 
	 * @param tatol
	 */
	public TicketCentre(int tatol) {
		this.tatol = this.current = tatol;
	}

	/**
	 * 購票
	 * 
	 * @param ticket
	 * @return
	 */
	public synchronized boolean buy(Ticket ticket) {
		ticket.setTime(new Date());
		if (!this.getFlag()) {// 還有餘票
			this.current = this.current - ticket.getNum();
			if (this.current >= 0) {
				if (this.current == 0) {// 當前已無票
					this.flag = true;
				}
				return true;
			} else {
				// 購買票數多於餘票
				this.current = this.current + ticket.getNum();
			}
		}
		return false;
	}

	/**
	 * 餘票查詢
	 * 
	 * @return
	 */
	public int getSurplus() {
		return this.current;
	}

	public int getTatol() {
		return tatol;
	}

	public int getCurrent() {
		return current;
	}

	public boolean getFlag() {
		return flag;
	}
}

輸出結果如下，因線程調度順序和結果不一：