jquery访问servlet并返回数据到页面



1，servlet:AjaxServlet.java

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);
    }

}

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

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;
}

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

<!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>