ServletActionContext.getResponse().setCharacterEncoding("utf-8");
PrintWriter out = ServletActionContext.getResponse().getWriter();
//out.print(jsonString.toString());
out.write(jsonString.toString());

backReasonManage = function() {

    var pageSize = 20;

    var reader = new Ext.data.JsonReader({
                root : 'dataList',
                totalProperty : 'total',
                id : 'id'
            }, [{name : 'id',mapping : 'id'},
                {name : 'backResult',mapping : 'backResult'}
                    ]);

    var store = new Ext.data.Store({
                url : 'getAllBackReasonMessage.action',
                reader : reader
            });
    

    store.load({
                params : {
                    start : 0,
                    limit : pageSize
                }
            });
    store.on('load',function(store){
        alert(store.getTotalCount());
    });
//    store.on('loadexception', function() {
////                store.removeAll();
////                bar.bind(store);
//                Ext.Msg.alert('查询', '数据加载错误！请重试');
//            });

    var colModel = new Ext.grid.ColumnModel([{
                            header : '序号',
                            whdth : 100,
                            sortable : true,
                            dataIndex : 'id'
                        },{
                            header : '退回原因',
                            width : 100,
                            sortable : true,
                            dataIndex : 'backResult'
                        }]);
    colModel.defaultSortable = true;

    var dataGrid = new Ext.grid.GridPanel({
                store : store,
                region : 'center',
                cm : colModel,
                stripeRows : true,
                viewConfig : {
                    forceFit : true
                },
                sm : new Ext.grid.RowSelectionModel({
                            singleSelect : true
                        }),
                trackMouseOver : false,
                loadMask : {
                    msg : '正在加载数据，请稍侯……'
                }
                //title : 'User Information List',
//                bbar : bar

            });

    var queryPanel = new Ext.Panel({
        title : "",
        layout : 'border',
        width : 800,
        height : 600,
        frame : true,
        border : true,

        buttonAlign : 'right',
        items : [dataGrid],
        buttons : [{
                    text : '新增',
                    handler : function() {
                        }, {
                    text : '修改',
                    handler : function() {
                        
                }
                ]
    });


    // 刷新
    function refreshGrid() {
        dataGrid.getStore().reload();
    };

};

Ext.extend(backReasonManage, Ext.Panel);
Ext.onReady(backReasonManage);

  var reader = new Ext.data.JsonReader({
                root : 'dataList',
                totalProperty : 'total',
                id : 'id'
            }, [{name : 'id',mapping : 'id'},
                {name : 'backResult',mapping : 'backResult'}
                    ]);

---