報錯信息:
Caused by: com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
No serializer found for class org.hibernate.proxy.pojo.bytebuddy.ByteBuddyInterceptor and
no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)
多對一或一對多關係時
懶加載的時候,查詢出的屬性爲空,序列化的時候報錯
需要讓序列化的時候忽略這些屬性
解決:
1.@JsonIgnoreProperties({ "hibernateLazyInitializer", "handler","報錯的屬性名"})
2.@JsonIgnore 放在字段上(方法)
報錯信息(在update的時候報這個錯誤,coupons在修改的時候傳入爲空)
Cascade="All-Delete-Orphan"
我的代碼:
@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "promotion_id")
private List<Coupon> coupons;
解決:
@OneToMany(fetch = FetchType.LAZY, cascade = {CascadeType.MERGE, CascadeType.REFRESH})
@JoinColumn(name = "promotion_id")
private List<Coupon> coupons;
不太懂內部映射關係和持久化機制,改bug是真心累啊--目前解決了,還要繼續看理論了。。。