时间:2021-07-01 10:21:17 帮助过:42人阅读
本文实例讲述了jquery访问servlet并返回数据到页面的方法。分享给大家供大家参考。具体实现方法如下:
1. servlet:AjaxServlet.java如下:
 代码如下: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);  
    }  
}
2. verify.js如下:
 代码如下: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=" + timstamp;  
    }else{  
        url = url + "?t=" + timstamp;  
    }  
    return url;  
}
3. 前台页面如下:
 代码如下:<!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>
希望本文所述对大家的Ajax程序设计有所帮助。