extjs json解析List数据

//下拉是json 解析
    var comboStore = new Ext.data.Store({
       proxy: new Ext.data.HttpProxy({  
                    url:'adminGroup',      //这里是struts请求到action
                    method:'POST'      //请求方式
                }),  
             reader: new Ext.data.JsonReader({            
                     //总记录数  
                    totalProperty: 'results',       //总记录数
                    root: 'items',     //记录集合
                    id:'roleId'
                },  
                 ['roleId','roleName']    //显示的两个字段
              )
    });

{"items":[{"password":"ahui","adminId":1,"role":{"roleName":"系统管理员","roleId":2,"sequence":"2","admin":null,"logoutMark":"否"},"adminName":"ahui","logout":"否"},{"password":"xiao","adminId":2,"role":{"roleName":"系统管理员","roleId":2,"sequence":"2","admin":null,"logoutMark":"否"},"adminName":"xiao","logout":"是"},"results":13}

这里是上面的格式

//下面是struts2里面的action代码 里面封装了ExtHelper工具类，里面有转换xml和json两种格式

public String findAll() throws Exception{

   HttpServletRequest request = ServletActionContext.getRequest();

   HttpServletResponse response = ServletActionContext.getResponse();

   List list = groupService.getGroup();   //调用service里面的方法，把所有的数据都查询出来

   String json = ExtHelper.getJsonFromList(list);//把list转换为json格式的数据

   response.setContentType("text/json;charset=UTF-8");//设置数据到前台显示的字符编码，如果不转会有乱码

   response.getWriter().write(json);

   System.out.println(json);

   return null;
}