CODEWITHSUNDEEP
springhibernatespring-data-jpaspring-datahibernate-mapping
John Doe
John Doe

Reputation: 2924

How to access the fields of an embedded class in Spring JPA

I have a class with 2 fields marked with @Id

 @Entity
 @Table(name="baspas")
class BasPas
  @Id
  @ManyToOne
  @JoinColumn(name="bas_id", referenceColumnName="id")
  private Bas basboard;

  @Id
  @ManyToOne
  @JoinColumn(name = "pas_id", referenceColumnName = "id")
  private pas pasboard;
 //

I refactored them to an Embedded class and pulled the above two @Id fields in the BasPasPK class. This will enable me to create an interface which will extend the JPARepository interface.

   @Embeddable
   class BasPasPK {

      @ManyToOne
      @JoinColumn(name="bas_id", referenceColumnName="id")
      private Bas basboard;

      @ManyToOne
      @JoinColumn(name = "pas_id", referenceColumnName = "id")
      private pas pasboard;
     //

   }

As both these fields are annotated @ManyToOne there is another end of the relationship, where in these fields are listed with "mappedBy". for eg.

   @Entity 
   class Another{
    .
    .

    @OneToMany(mappedBy = "basboard" cascade = CascadeType.ALL)
    private set<BasPas> basPas;
    .
    .
    .
}

But after refactoring how to access the other end of the class.

What I mean is when I am doing mvn spring-boot:run I am getting the following exception

org.hibernate.AnnotationException: mappedBy reference an unknown target entity property

then what I did was to change the class name in 

 @Entity
class Another{
        .
        .

        @OneToMany(mappedBy = "basboard" cascade = CascadeType.ALL)
        private Set<BasPas> basPas;
        .
        .
        .
    }

to this

 class Another{
    .
    .

    @OneToMany(mappedBy = "bas" cascade = CascadeType.ALL)
    private set<BasPasPk> basPas; //changed the classname in angle brackets to BasPasPk
    .
    .
    .
}

But after this I started getting this following exception.

org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class.

How to fix this, I mean how to access these properties in the other class after pulling those two property in the embedded class.

Upvotes: 0

Views: 673

Answers (2)

Selindek
Selindek

Reputation: 3423

try it this way: (Assuming the name of the BasPasPK property in your entity is id)

 @Entity
class Bas{
        .
        .

        @OneToMany(mappedBy = "id.basboard" cascade = CascadeType.ALL)
        private Set<BasPas> basPas;
        .
        .
        .
    }

Upvotes: 2

Ver
Ver

Reputation: 348

Have you tried annotating the class BasPas with @Entity ?

Upvotes: 1

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