JPA Hibernate中介表 - 重新提交 [英] JPA Hibernate intermediary table - resubmitted

问题描述

原始问题的改写：

我有你的典型M：​​M关系，在我看来， User

USER，ROLE，USER_ROLE

我需要第二个USER_ROLE表，匹配 User s到 Role s。我不会详细说明这是为什么（除非你需要我），但我正在寻找一种方法来完成这与JPA和不改变用户和角色实体。

*我需要第二个USER_ROLE表来审核

> >解决方案

您可能需要使用内部回调方法，当实体的生命周期发生变化时（根据您的需要），它将在审计日志中创建一个条目。

回调注释不言自明

  @PrePersist void onPrePersist（）{} 
 @PostPersist void onPostPersist（）{} 
 @PostLoad void onPostLoad（）{} 
 @PreUpdate void onPreUpdate（）{} 
 @PostUpdate void onPostUpdate（）{} 
 @PreRemove void onPreRemove （）{} 
 @PostRemove void onPostRemove（）{} 
  

注释的一个href =http://docs.oracle.com/javaee/6/api/javax/persistence/PostUpdate.html =nofollow>文档：

用于指定相应生命周期
事件的回调方法。这个注解可以应用于实体类的方法，
映射超类或回调监听器类。

Rephrase of original question:

I have your typical M:M relationship, in my case think of the User/Role example:

USER, ROLE, USER_ROLE

I need a second USER_ROLE table matching up Users to Roles. I won't get into specifics as to why that is (unless you need me to), but I am looking for a way to accomplish this with JPA AND without changing up the User and Role Entities.

*I need a second USER_ROLE table to audit actions the User performs and which Role he was at the time the action was performed.*

解决方案

You may want to use a internal callback method that will create an entry in the audit log whenever the lifecycle of the entity changes (according to your needs).

The callback annotations are self-explanatory more or less:

@PrePersist void onPrePersist() {}
@PostPersist void onPostPersist() {}
@PostLoad void onPostLoad() {}
@PreUpdate void onPreUpdate() {}
@PostUpdate void onPostUpdate() {}
@PreRemove void onPreRemove() {}
@PostRemove void onPostRemove() {}

I quote from the documentation of the annotations:

Is used to specify callback methods for the corresponding lifecycle event. This annotation may be applied to methods of an entity class, a mapped superclass, or a callback listener class.

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