使用带有3层结构的@IdClass,在主键中使用复合键进行Hibernate映射

这个问题非常类似于：JPA (Hibernate, EclipseLink) mapping: why doesn’t this code work (chain of 2 relationships using JPA 2.0, @EmbeddedId composite PK-FK)?

实际上我的唯一(从我发现的有意义的)差异是我使用@IdClass并且我很可能无法切换到与hibernate不同的提供者.

但无论如何这里是代码(删除不重要的部分)：

PermissionContextType.java：

@Entity
@IdClass(PermissionContextTypePk.class)
public class PermissionContextType{
   @Id    
   private String id;    

   @Id
   @JoinColumn (name = "PROJECT", referencedColumnName = "ID")
   @ManyToOne ()
   private Project project;

   public static class PermissionContextTypePk implements Serializable{
       public String project;
       public String id;
       // ... eq and hashCode here ...
   }

}

PermissionContext.java：

@Entity
@IdClass(PermissionContextPk.class)
public class PermissionContext{
   @Id
   private String id;

   @Id
   @JoinColumns ({
            @JoinColumn (name = "PROJECT", referencedColumnName = "PROJECT"),
            @JoinColumn (name = "PERMISSIONCONTEXTTYPE", referencedColumnName = "ID")
        })
   @ManyToOne
   private PermissionContextType permissionContextType;

   public static class PermissionContextPk implements Serializable{
      public String id;
      public PermissionContextTypePk permissionContextType;
      // ... eq and hashCode here ...
   }
}

Permission.java：

@Entity
@IdClass(PermissionPk.class)
public class Permission{

   @Id
   private String id;

   @Id
   @JoinColumns ({
            @JoinColumn (name = "PROJECT", referencedColumnName = "PROJECT"),
            @JoinColumn (name = "PERMISSIONCONTEXTTYPE", referencedColumnName = "PERMISSIONCONTEXTTYPE"),
            @JoinColumn (name = "PERMISSIONCONTEXT", referencedColumnName = "ID")
        })
   @ManyToOne
   private PermissionContext permissionContext;

   public static class PermissionPk implements Serializable{
      public String id;        
      public PermissionContextPk permissionContext;
      // ... eq and hashCode here ...
   }
}

而我得到的是：

 org.hibernate.AssertionFailure: Unexpected nested component on the referenced entity when mapping a @MapsId: PermissionContext 
    Caused by: org.hibernate.AssertionFailure: org.hibernate.AssertionFailure: Unexpected nested component on the referenced entity when mapping a @MapsId: PermissionContext

有没有人知道这是一个hibernate错误,我应该将它发布在他们的问题跟踪系统上(并祈祷我能够更新到给定的hibernate版本)或者我的绑定实体的方式是否存在根本错误？

我已经使用EAP 6.1(4.2.0)上的hibernate实现以及wildfly(不知道哪一个)进行了检查.

解决方法:

好的,所以这是我到目前为止所发现的：

谢谢我的朋友：https://hibernate.atlassian.net/browse/HHH-5764,这很可能是这种行为的原因.

我发现了一个解决方法：

Permission.java：

@Entity
@IdClass(PermissionPk.class)
public class Permission{

   @Id
   private String id;

// for the next 3 fields there are no public acessors, so the public API of the class was not changed !
   @Id
   @Column(name = "PROJECT")
   private String projectId;

   @Id
   @Column(name = "PERMISSIONCONTEXTTYPE")
   private String permissionContextTypeId;

   @Id
   @Column(name = "PERMISSIONCONTEXT")
   private String permissionContextId;


   @JoinColumns ({
            @JoinColumn (name = "PROJECT", referencedColumnName = "PROJECT", updatable = false, insertable = false),
            @JoinColumn (name = "PERMISSIONCONTEXTTYPE", referencedColumnName = "PERMISSIONCONTEXTTYPE", updatable = false, insertable = false),
            @JoinColumn (name = "PERMISSIONCONTEXT", referencedColumnName = "ID", updatable = false, insertable = false)
        })
   @ManyToOne
   private PermissionContext permissionContext;

   public static class PermissionPk implements Serializable{      
// previously they where private as well, but removed public constructor for the sake of simplicity of the question - so no changes where necesary in public API of the class !
      private String id;        
      private String projectId;        
      private String permissionContextTypeId;
      private String permissionContextId;

   public PermissionPk () {}

    public PermissionPk (String aId, PermissionContextPk aPermissionContext) {
        this.id = aId;
        permissionContextId = aPermissionContext.id;
        permissionContextTypeId = aPermissionContext.permissionContextType.id;
        projectId = aPermissionContext.permissionContextType.project;
    }  
... eq and hashCode here ...
   }
}

这种解决方法的好处是它不会以任何方式更改类的公共API
(唯一的变化是我需要在Perk中显示Pk的上下文和上下文类型的字段 – 它们之前只有一个公共构造函数的私有[但是再次简化了问题]),也没有改变jpql查询,同时解决方法是可扩展的(对任何层数 – 只要每个偶数pk不包含另一个pk),所以如果错误将被解决,将很容易删除变通方法.

我仍然乐意接受对我的解决方法或问题本身的任何评论.

标签：java,jpa,hibernate,java-ee-6
来源： https://codeday.me/bug/20190708/1403548.html