Spring MVC 抛出 500 Could not write content 异常

Spring MVC 异常：

HTTP Status 500 - Could not write content: No serializer found for class org.seckill.dto.Exposer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: org.seckill.dto.SeckillResult["data"]); 

解决方案：

对象中里面 没有设置get/set方法