Servlet笔记11--补充

Servlet线程安全问题：

　

　　代码示例：

 package com.bjpowernode.javaweb.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 RegisterServlet extends HttpServlet {

     private static final long serialVersionUID = 1L;

     //实例变量
     private String username;

     @Override
     protected void doPost(HttpServletRequest request, HttpServletResponse response)
             throws ServletException, IOException {

         response.setContentType("text/html;charset=UTF-8");
         PrintWriter out = response.getWriter();
         request.setCharacterEncoding("UTF-8");

         //局部变量
         //String username = request.getParameter("username");

         synchronized(this){
             //实例变量
             username = request.getParameter("username");
             out.print("恭喜你" + username + "注册成功");
         }
     }

 }

路径编写总结：