servlet多线程并发小实例

墨蓝 2022-08-06 14:29 189阅读 0赞

HelloServlet.java文件如下:

package com.test.servlet;

import java.io.IOException;  
  
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
public class HelloServlet extends HttpServlet  
\{  
    private String username ;   //username 定义成了成员变量，造成了多线程问题  
      
    @Override  
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)  
            throws ServletException, IOException  
    \{  
        this.username = req.getParameter("username");  
          
        //进行后端的一些业务处理  
        try  
        \{  
            Thread.sleep(10000);  
        \}  
          
        catch(Exception e )  
        \{  
            e.printStackTrace();  
        \}  
          
          
        req.setAttribute("username" ,this.username);  
        req.getRequestDispatcher("hello.jsp").forward(req,resp);  
    \}  
\}

form.jsp文件的内容如下:

<%@ page language="java" import="java.util.\*" pageEncoding="UTF-8"%>  
<%  
String path = request.getContextPath();  
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";  
%>  
  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
<html>  
  <head>  
    <base href="<%=basePath%>">  
      
    <title>My JSP 'form.jsp' starting page</title>  
      
    <meta http-equiv="pragma" content="no-cache">  
    <meta http-equiv="cache-control" content="no-cache">  
    <meta http-equiv="expires" content="0">      
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">  
    <meta http-equiv="description" content="This is my page">  
      
  
  </head>  
   
  <body>  
    <form action="HelloServlet">  
        username:<input type="text" name="username"><br>  
          
        <input type="submit" value="submit">  
    </form>  
      
      
  </body>  
</html>

hello.jsp文件的内容是:

<%@ page language="java" import="java.util.\*" pageEncoding="UTF-8"%>  
<%  
String path = request.getContextPath();  
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";  
%>  
  
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
<html>  
  <head>  
    <base href="<%=basePath%>">  
      
    <title>My JSP 'hello.jsp' starting page</title>  
      
    <meta http-equiv="pragma" content="no-cache">  
    <meta http-equiv="cache-control" content="no-cache">  
    <meta http-equiv="expires" content="0">      
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">  
    <meta http-equiv="description" content="This is my page">  
      
  
  </head>  
   
  <body>  
    username: <%= request.getAttribute("username") %>  
  
  
  </body>  
</html>