简单的网页计数器

根据上篇讲的session，我们来做一个计数器！

代码如下：

package com.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;
import javax.servlet.http.HttpSession;

public class Counter extends HttpServlet {

 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  //创建session
  HttpSession session=request.getSession(true);
  
  Object count=session.getAttribute("COUNTER");
  
  int counter=0;
  
  if(count==null)
  {
   counter=1;
   //第一次计数存入session
   session.setAttribute("COUNTER", new Integer(1));
  }
  else
  {
   counter=((Integer)count).intValue();
   //计数+1
   counter++;
   //将计数存入session
   session.setAttribute("COUNTER", counter);
   
  }
  PrintWriter out = response.getWriter();
  
  out.println("欢迎！您第"+counter+"次访问！");
 
  out.flush();
  out.close();
 
 }
 public void doPost(HttpServletRequest request, HttpServletResponse response)
 throws ServletException, IOException {
  
  doGet(request,response);
  
 }

}
访问时，并且刷新页面的时候，效果如下图所示：

 

每天一点点希望对大家有利！