请问EXTJS为何接收到不到action传输的数据啊？！

Question

这是我的代码，求高手解答，非常感谢！！！
jsp中
Ext.onReady(function(){
    // create the Data Store  
    var store = new Ext.data.JsonStore({
        root: 'list',
        totalProperty: 'totalCount',
        idProperty: 'threadid',
        remoteSort: true,
        fields: [
            'stuId', 'stuName', 'stuSex', 'StuClass'
        ],
        proxy: new Ext.data.HttpProxy({
            url:'list_json'
        }),
    });
    // trigger the data store load  
    store.load({params:{start:0, limit:5}});    var grid = new Ext.grid.GridPanel({
        width:550,
        height:300,
        title:'ExtJS.com - Browse Forums',
        store: store,
        trackMouseOver:false,
        disableSelection:true,
        loadMask: true,
        // grid columns  
        columns:[{
            header: "学号",
            dataIndex: 'stuId',
            width: 220,
            sortable: false
        },{  
            header: "姓名",
            dataIndex: 'stuName',
            width: 100,
            sortable: false
        },{  
            header: "性别",
            dataIndex: 'stuSex',
            width: 70,
            align: 'right',
            sortable: false
        },{  
            header: "班级",
            dataIndex: 'stuClass',
            width: 150,
            sortable: false
        }],  
        // paging bar on the bottom  
        bbar: new Ext.PagingToolbar({
            pageSize:5,
            store: store,
            displayInfo: true,
            displayMsg: 'Displaying topics {0} - {1} of {2}',
            emptyMsg: "No topics to display",
            items:[
                '-', {
                pressed: true,
                enableToggle:true,
                text: 'Show Preview',
                cls: 'x-btn-text-icon details',
                toggleHandler: function(btn, pressed){
                    var view = grid.getView();
                    view.showPreview = pressed;
                    view.refresh();
                }
            }]
        })
    });
    // render it  
    grid.render('gridview');
});            
struts.xml中
<package name="extjs" extends="json-default">
        <default-action-ref name="login" />
        <action name="*_json" class="studentAction" method="{1}">
            <result type="json"></result>
        </action>
    </package>
acton.中
public String list(){
//得到response对象
HttpServletResponse response = ServletActionContext.getResponse();
try {
PrintWriter out = response.getWriter();// 得到输出对象
System.out.println("执行到action了");
String list = studentBiz.getStudenPaginationInfoToJson(start, limit);
if (list != null) {
StringBuilder stulist = new StringBuilder();
stulist.append("{totalCount:36,list:");
stulist.append(list);
stulist.append("}");
response.setCharacterEncoding("UTF-8");
out.print(stulist.toString());
// return null;
System.out.println("执行到action了3");
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
急求高手解答，感激不尽！！ext struts extjsjavascript

Answer 1

var store = new Ext.data.JsonStore({
        totalProperty: 'totalCount',
        idProperty: 'threadid',
        remoteSort: true,
root:'root', 
         proxy:{
fields: ['stuId', 'stuName', 'stuSex', 'StuClass'], //顺序
            url:'list_json',
type:'ajax',
reader:'json'
}
       
    });

Answer 2

Ext.define('MyApp.store.MyJsonStore', {
    extend: 'Ext.data.Store',        constructor: function(cfg) {
        var me = this;
        cfg = cfg || {};
        me.callParent([Ext.apply({
//            autoLoad: true,
           fields: [｛'stuId'｝,｛ 'stuName'｝, ｛'stuSex'｝, ｛'StuClass'｝], //
            storeId: 'store',
            
            proxy: {
                type: 'ajax',                reader: {
                    type: 'json',
                    root: 'list'
                }
            }
        }, cfg)]);
    }
});