package com.lc.servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class Ticketsell extends HttpServlet { public int ticket = 3;//假設只有三張票   public void doGet(HttpServletRequest request, HttpServletResponse response)  throws ServletException, IOException { PrintWriter out = response.getWriter(); response.setContentType("text/html;charset=gbk");   //簡單點而處理售票問題 //當一個變量需要多個用戶共享，則應該在訪問該變量的時候加 同步機制 //如果一個變量不需要共享則直接在doGet()和doPost()方法中定義即可,這樣的話就不存在線程的安全型問題   synchronized (this) { //解決同步性問題的方法    if(ticket > 0)  {  System.out.println("你買到票了！");  out.println("你買到票了！");    //休眠  try {   Thread.sleep(10*1000);  } catch (InterruptedException e) {   // TODO Auto-generated catch block   e.printStackTrace();  }  ticket--;  }  else  {  System.out.println("你沒有買到票！");  out.println("你沒有買到票！");  } }  }  public void doPost(HttpServletRequest request, HttpServletResponse response)  throws ServletException, IOException {   this.doGet(request, response); }}