javascript - extJS 3.3.0 网格错误，未显示 JSON 数据

Question

我已将我的商店配置为：听到 url:pattern 是我的 resteasy webservice 应用程序路径：

Ext.BLANK_IMAGE_URL = '/ext-3.3.0/resources/images/default/s.gif';
var store = new Ext.data.Store({
    proxy : new Ext.data.HttpProxy({
        url:"/RestEasyDemo2/stud/student/read",
        method:"GET"
    }),
    reader: new Ext.data.JsonReader({
        fields:['id','name','address','gerder','emailId','contactNo'],
        //id:'id',
        root:'listing' // it's @XmlRootElement(name = "listing") of my list class
    })

});
store.load();

网格面板代码是，

var grid = new Ext.grid.GridPanel({
    store:store,
    columns:[{header:'Id', width:170 , sortable:true, dataIntex:'id'},
             {header:'NAME', width:170 , sortable:true, dataIntex:'name'},
             {header:'Address', width:150 , sortable:true, dataIntex:'address'},
             {header:'Gender', width:150 , sortable:true, dataIntex:'gender'},
             {header:'EMAIL ', width:150 , sortable:true, dataIntex:'emailId'},
             {header:'ContactNo ', width:100 , sortable:true, dataIntex:'contactNo'}
             ],
    title:'My Contacts',
    autoHeight:true,
    width:590,
    renderTo: Ext.getBody(),
    loadMask: true,
    //renderTo:document.body(),
    fram:true
}); 

但是，json数据没有被显示......所以请告诉我我实际缺少什么......？