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;

    }