Hibernate (JPA) inheritance mapping of abstract super classes

Use:

    @Entity
    @Inheritance(strategy = InheritanceType.JOINED)
    AbstractLegalEntity

In the database you will have one table for AbstractLegalEntity, and tables for classes, which extend AbstractLegalEntity class. You won't have instances of AbstractLegalEntity if it's abstract. Polymorphism can be used here.

When you use:

    @MappedSuperclass
    AbstractLegalEntity
    
    @Entity
    ConcretePersonEntity extends AbstractLegalEntity

This will create only one table in your database called ConcretePersonEntity, containing columns from both classes.

Add @Entity annotation to AbstractLegalEntity. Instance of AbstractLegalEntity will never exist - hibernate will load appropriate extending instances - ConcreteBusinessEntity or ConcretePersonEntity according to Id field.