net.sf.json.JSONException: There is a cycle in the hierarchy!

项目中使用了AJAX技术，JAR包为：json-lib.jar， 在开发过程中遇到了一个JSON-LIB和Hibernate有关的问题：

net.sf.json.JSONException: There is a cycle in the hierarchy!
 at net.sf.json.util.CycleDetectionStrategy$StrictCycleDetectionStrategy.handleRepeatedReferenceAsObject(CycleDetectionStrategy.

主外键关联，产生循环错误

需设置过滤，去掉关联

Java

    public ModelAndView getRooms(HttpServletResponse response,@PathVariable Long hotelsid){
        List<Room> roomList=roomService.findByHotelsid(hotelsid);
        JsonConfig jsonConfig = new JsonConfig();
        jsonConfig.setJsonPropertyFilter(new net.sf.json.util.PropertyFilter(){
            @Override
            public boolean apply(Object source, String name, Object value) {
                if(name.equals("hotels")){
                    return true;
                }else{
                return false;
                }
            }});
        
        JSONArray json=JSONArray.fromObject(roomList,jsonConfig);
        
        try {
            PrintWriter out=response.getWriter();
            out.println(json.toString());
            out.flush();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        return null;
    }