使用多线程实现取票操作

假设票数为100，四个人需要完成取票的操作，每次取票间隔为一秒

package 用多线程并发实现购票;

public class Ticket {
    private int num;

    public Ticket(int num) {
        this.num = num;
    }

    public Ticket() {
    }

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

    public int getNum() {
        return num;
    }
    public void buy(){
        synchronized (this){
            int before= this.getNum();
            int after= this.getNum()-1;
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            this.setNum(after);
        }

    }
}

package 用多线程并发实现购票;

public class TicketThread extends Thread{
    private Ticket ticket;

    public TicketThread() {
    }

    public TicketThread(Ticket ticket) {
        this.ticket = ticket;
    }
    public void run(){
        ticket.buy();
        System.out.println(Thread.currentThread().getName()+"购买了一张票，还剩余："+ticket.getNum());
    }
}

package 用多线程并发实现购票;

public class Test {
    public static void main(String[] args) {
        Ticket ticketnum=new Ticket(100);
        TicketThread t1=new TicketThread(ticketnum);
        TicketThread t2=new TicketThread(ticketnum);
        TicketThread t3=new TicketThread(ticketnum);
        TicketThread t4=new TicketThread(ticketnum);
        t1.setName("rose");
        t2.setName("jennie");
        t3.setName("jack");
        t4.setName("lisa");
        t1.start();
        t2.start();
        t3.start();
        t4.start();
    }
}

测试的结果如下，测试正确

rose购买了一张票，还剩余：99
lisa购买了一张票，还剩余：98
jack购买了一张票，还剩余：97
jennie购买了一张票，还剩余：96