jquery实时数据更新

最近用jquery写了一个客户端实时刷新的小例子，代码如下
客户端html代码

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <title>实时显示数据</title>
    <script type="text/javascript" src="jslib/jquery.js"></script>
    <script type="text/javascript" src="jslib/player.js"></script>
</head>
<body>
   <div id="0001"><a href="#">许飞:</a><span></span></div>
   <div id="0002"><a href="#">孙燕姿:</a><span></span></div>

   <div id="player">
       <div id="yesterday">昨天:<span></span></div>
       <div id="now">现在:<span></span></div>
   </div>
</body>
</html>

js代码

var obj;
var id;
$(document).ready(function() {
    var playerdiv = $("#player").css("border","1px solid black").width("100px").css("position","absolute").css("z-index",100);
    playerdiv.hide();
    var as = $("a");
    as.mouseover(function(event) {
        var aNode = $(this);
        var parentNode = aNode.parent();

        id = parentNode.attr("id");
        var myEvent = event || window.event;
        playerdiv.css("left",myEvent.clientX + 10 + "px").css("top",myEvent.clientY + 10 + "px");
        updata();

        playerdiv.show();

    });
    as.mouseout(function() {
        playerdiv.hide();
    });
    getInfo();
    setInterval(getInfo, 1000);     //设置定时器函数，每个1000毫秒执行一次
});

function getInfo() {
    $.get("GetPlayerInfo", null, function(data) {
        //obj = eval(data);     //如果指明返回的类型为json格式就不必用eval方法转化
        obj = data;
        var player1 = obj["0001"];
        var player2 = obj["0002"];

        var span1 = $("#0001").children("span");

        span1.html(player1.now);

        var span2 = $("#0002").children("span");
        span2.html(player2.now);

        updata();
    },"json");

}

function updata() {
    var player = obj[id];
    for (var property in player) {
        if (property != "name") {
            $("#"+property).children("span").html(player[property]);
        }
    }
}

服务器端代码，我用的是Servlet

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import javax.servlet.ServletConfig;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;

/**
 * Created by IntelliJ IDEA.
 * User: Administrator
 * Date: 2011-4-12
 * Time: 10:07:49
 * To change this template use File | Settings | File Templates.
 */
public class GetPlayerInfo extends HttpServlet {
    private HashMap<String, Player> players = null;

    public void init(ServletConfig servletConfig) throws ServletException {
        players = new HashMap<String, Player>();
        Player player1 = new Player("0001", "许飞", 1005.0);
        Player player2 = new Player("0002", "孙燕姿", 1100.0);
        players.put(player1.getId(), player1);
        players.put(player2.getId(), player2);

    }

    protected void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
        doGet(httpServletRequest, httpServletResponse);
    }

    protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
        httpServletResponse.setContentType("text/html;charset=UTF-8");
        httpServletResponse.setHeader("Cache-Control","no-cache");

        Player player1 = players.get("0001");
        Player player2 = players.get("0002");
        double temp = Math.random() * 10;
        temp = (int)(temp + player1.getNow())*100/100;
        player1.setNow(temp);

        temp = Math.random() * 10 + 5;
        temp = (int)(temp + player2.getNow())*100/100;
        player2.setNow(temp);

        StringBuilder builder = new StringBuilder();        //返回的是json数据的格式
        builder.append("({\"").append(player1.getId()).append("\":")
                .append("{name:\"").append(player1.getName())
                .append("\",yesterday:").append(player1.getYesterday())
                .append(",now:").append(player1.getNow())
                .append("},")
                .append("\"").append(player2.getId()).append("\":")
                .append("{name:\"").append(player2.getName())
                .append("\",yesterday:").append(player2.getYesterday())
                .append(",now:").append(player2.getNow())
                .append("}})");
        PrintWriter out = httpServletResponse.getWriter();
        System.out.println(builder);
        out.print(builder);
    }
}

bean的代码如下

/**
 * Created by IntelliJ IDEA.
 * User: Administrator
 * Date: 2011-4-12
 * Time: 10:05:55
 * To change this template use File | Settings | File Templates.
 */
public class Player {
    private String id;
    private String name;
    private double yesterday;
    private double now;

    public Player(String id, String name, double yesterday) {
        this.id = id;
        this.name = name;
        this.yesterday = yesterday;
        this.now = yesterday;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public double getYesterday() {
        return yesterday;
    }

    public void setYesterday(double yesterday) {
        this.yesterday = yesterday;
    }

    public double getNow() {
        return now;
    }

    public void setNow(double now) {
        this.now = now;
    }
}