I have class named AbstractEntity, which is annotated with @MappedSuperclass. Then I have a class named User (@Entity) which extends AbstractEntity. Both of these exist in a package named foo.bar.framework. When I use these two classes, everything works just fine. But now I've imported a jar containing these files to another project. I'd like to reuse the User class and expand it with a few additional fields. I thought that @Entity public class User extends foo.bar.framework.User
would do the trick, but I found out that this implementation of the User only inherits the fields from AbstractEntity, but nothing from foo.bar.framework.User. The question is, how can I get my second User class to inherit all the fields from the first User entity class?
Both User class implementation have different table names defined with @Table(name = "name").
My classes look like this
package foo.bar.framework;
@MappedSuperclass
abstract public class AbstractEntity {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
protected Long id;
@Column(nullable = false)
@Version
protected Long consistencyVersion;
...
}
package foo.bar.framework;
@Entity
@Table(name = "foouser")
public class User extends AbstractEntity {
protected String username;
protected String password;
....
}
package some.application;
@Entity
@Table(name = "myappuser")
public class User extends foo.bar.framework.User {
protected String firstname;
protected String lastname;
protected String email;
....
}
With the code above, EclipseLink will create a table named "myappuser" containing the fields "id", "consistencyVersion", "firstname", "lastname" and "email". The fields "usernam开发者_运维知识库e" and "password" are not created to the table - and that is the problem I'm having.
With JPA, the default inheritance strategy (i.e. when not specified) is SINGLE_TABLE
: there is only one table per inheritance hierarchy and all fields are persisted in the table of the base class.
If you want to have a table for each class in the inheritance hierarchy and each table to contain columns for all inherited fields, you need to use a TABLE_PER_CLASS
strategy.
package foo.bar.framework;
@MappedSuperclass
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
abstract public class AbstractEntity {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
protected Long id;
@Column(nullable = false)
@Version
protected Long consistencyVersion;
...
}
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