package com.panlong.servlet; 

import java.io.IOException; 
import java.io.PrintWriter; 
import java.net.URLDecoder; 

import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

public class AjaxServlet extends HttpServlet { 
    private static final long serialVersionUID = 1L; 
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) 
            throws ServletException, IOException { 
        Integer total = (Integer) req.getSession().getAttribute("total"); 
        int temp = 0; 
        if(total == null ){ 
            temp = 1; 
        }else{ 
            temp = total.intValue() + 1; 
        } 
    req.getSession().setAttribute("total",temp); 
        try { 
            //1.取参数 
            resp.setContentType("text/html;charset=GBK"); 
            PrintWriter out = resp.getWriter(); 
            String old = req.getParameter("name"); 
            //2.检查参数是否有问题 
            //String name = new String(old.getBytes("iso8859-1"),"UTF-8"); 
            String name = URLDecoder.decode(old,"UTF-8"); 
            if("".equals(old) || old == null){ 
                out.println("用户名必须输入"); 
            }else{ 
                if("liling".equals(name)){ 
                    out.println("恭喜登录成功"); 
                    return; 
                }else{ 
                    out.println("该用户名未注册，您可以注册["+name+"]这个用户名"+temp); 
                } 
            } 
        } catch (Exception e) { 
            // TODO Auto-generated catch block 
            e.printStackTrace(); 
        } 
        //3.检验操作 
    } 
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
            throws ServletException, IOException { 
        doGet(req, resp); 
    } 
}

function verify(){ 
    //解决中文乱码问题的方法1,页面端发出的数据作一次encodeURI，服务端使用new String(old.getBytes("iso8859-1"),"UTF-8"); 
    //解决中文乱码问题的方法2,页面端发出的数据作两次encodeURI,服务端使用String name = URLDecoder.decode(old,"UTF-8"); 
    var url = "servlet/AjaxServlet?name="+encodeURI(encodeURI($("#userName").val())); 
    url = convertURL(url); 
    $.get(url,null,function(data){ 
        $("#result").html(data); 
    }); 
} 
//给url地址增加时间蒫，难过浏览器，不读取缓存 
function convertURL(url){ 
    //获取时间戳 
    var timstamp = (new Date()).valueOf(); 
    //将时间戳信息拼接到url上 
    if(url.indexOf("?") >=0){ 
        url = url + "t=" + timst 
    }else{ 
        url = url + "?t=" + timst 
    } 
    return url; 
}

!DOCTYPE html> 
html> 
  head> 
    title>AJAX实例/title> 
    meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
    meta http-equiv="description" content="this is my page"> 
    meta http-equiv="content-type" content="text/html; charset=GBK"> 
    script type="text/javascript" src="js/verify.js">/script> 
    script type="text/javascript" src="js/jquery.js">/script> 
    !--link rel="stylesheet" type="text/css" href="./styles.css">--> 
  /head> 
  body> 
        font color="blue" size="2">请输入用户名：/font>  
         input type="text" id="userName" />font color="red" size="2">span id="result" >*/span>/font>br/>br/> 
         !-- div id="result">/div> --> 
          input type="submit" name="提交" value="提交"  onclick="verify()"/> 
  /body>
/html>