Ext json GRID 分页问题 高手解答

08-02-01.html
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=gbk">
        <title>03.grid</title>
        <link rel="stylesheet" type="text/css" href="../../resources/css/ext-all.css" />
        <script type="text/javascript" src="../../adapter/ext/ext-base.js"></script>
        <script type="text/javascript" src="../../ext-all.js"></script>
        <script type="text/javascript">
Ext.onReady(function(){    var cm = new Ext.grid.ColumnModel([
        {header:'编号',dataIndex:'id'},
        {header:'名称',dataIndex:'name'},
        {header:'描述',dataIndex:'descn'}
    ]);    var store = new Ext.data.Store({
        proxy: new Ext.data.HttpProxy({url:'08_02_01.jsp'}),
        reader: new Ext.data.JsonReader({
            totalProperty: 'totalProperty',
            root: 'root'
        }, [
            {name: 'id'},
            {name: 'name'},
            {name: 'descn'}
        ])
    });    var grid = new Ext.grid.GridPanel({
        renderTo: 'grid',
        autoHeight: true,
        store: store,
        cm: cm,
        bbar: new Ext.PagingToolbar({
            pageSize: 10,
            store: store,
            displayInfo: true,
            displayMsg: '显示第 {0} 条到 {1} 条记录，一共 {2} 条',
            emptyMsg: "没有记录"
        })
    });
    store.load({params:{start:0,limit:10}});});
        </script>
    </head>
    <body>
        <script type="text/javascript" src="../examples.js"></script>
        <div id="grid" style="height:265px;"></div>
    </body>
</html>
================================================================================
8.2.1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP '8.2.1.jsp' starting page</title>
    
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->  </head>
  
  <body>
    <%
String start = request.getParameter("start");
String limit = request.getParameter("limit");
try {
    int index = Integer.parseInt(start);
    int pageSize = Integer.parseInt(limit);

    String json = "{totalProperty:100,root:[";
    for (int i = index; i < pageSize + index; i++) {
        json += "{id:" + i + ",name:'name" + i + "',descn:'descn" + i + "'}";
        if (i != pageSize + index - 1) {
            json += ",";
        }
    }
    json += "]}";
    response.getWriter().write(json);
} catch(Exception ex) {
}
System.out.println(start);
System.out.println(limit);
%>

  </body>
</html>
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为什么显示出来没有数据