System.out.println("order:"+order);
        
        JsonConfig config = new JsonConfig();    
        config.setIgnoreDefaultExcludes(false);       
        config.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);     
        config.setExcludes(new String[]{//只要設(shè)置這個數(shù)組，指定過濾哪些字段。    
           "id"
        });
        String param = JSONObject.fromObject(order, config).toString();
        System.out.println("param:"+param);

***

                 JsonConfig config = new JsonConfig();  
         config.setJsonPropertyFilter(new PropertyFilter()  
        {  
          @Override  
           public boolean apply(Object source, String name, Object value)  
               {  
               return value == null;  
           }  
        });  
        json.put("posUser", JSONObject.fromObject(posUserWithBLOBs,config).toString());