Replace entity's list instead of adding to it when updating

Question

FooObject has an entity with a few lists of bar objects managed by entities. Whenever I edit FooObject and call update on it, all of those lists are added to, not replaced.

   @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, 
              mappedBy = "barEntity", targetEntity = BarTypeAEntity.class)
   private List<BarTypeAEntity> barTypeAs;

I can first remove all the lists before calling update but in auditing these tables it appears as a delete then an new creation, rather than just one update.

How can I just simply overwrite rather than append these lists

Answer 1

Use orphanRemoval = true. This tells Hibernate that if you remove BarTypeAEntity object from the collection of barTypeAsand then save FooObject, the removed BarTypeAEntityshould be deleted from the underlying DB.

@OneToMany( cascade = CascadeType.ALL, fetch = FetchType.LAZY, 
              mappedBy = "barEntity", targetEntity = BarTypeAEntity.class,
              orphanRemoval = true )

private List<BarTypeAEntity> barTypeAs;

And do something like this for update

foo.getBarTypeAs().clear();
foo.getBarTypeAs().add(new BarTypeAEntity());