多线程 买票

package com.zuosy.learn;

import java.util.HashMap;
import java.util.Iterator;

public class App {
    public static void main(String[] args) {
        MaiPiao piao = new MaiPiao(150);

        Thread[] threads = new Thread[3];
        String[] threadName = {"DM", "HN", "OL"};
        
        for (int index = 0; index < threads.length; ++index) {
            threads[index] = new Thread(piao); 
            threads[index].setName(threadName[index]);
            piao.AddRecord(threads[index].getName());
        }

        for(Thread thread : threads) {
            thread.start();
        }

        System.out.println("Done");
    }
}

class MaiPiao implements Runnable {

    private Long ticket;
    private HashMap<String, Integer> ticketRecord = 
                    new HashMap<String, Integer>();
    private String threadName;

    public MaiPiao(long ticket) {
        this.ticket = ticket;
    }
    
    public void AddRecord(String thread) {
        ticketRecord.put(thread, 0);
    }
    
    @Override
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        
        Iterator<String> it = ticketRecord.keySet().iterator();
        while (it.hasNext()) {
            String key = it.next();
            buffer.append(key).append(" : ").append(ticketRecord.get(key)).append('\n');
        }
        return buffer.toString();
    }

    public void run() {
//        System.out.println("run:" + this);
        while (true) {
            System.out.println(Thread.currentThread().getName());
            try {
                Thread.sleep((long) (Math.random() * 5));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (this) {
                threadName = Thread.currentThread().getName();
                if (ticket > 0) {
                    System.out.println(threadName + " ticket = " + ticket--);
                    ticketRecord.replace(threadName, ticketRecord.get(threadName) + 1);
                    if (ticket <= 0)
                        break;
                }
                else {
                    System.out.println(Thread.currentThread().getName() + "break");
                    return;
                }
            }
        }

        System.err.println(this);
    }
}