@Documented @Target(TYPE) @Retention(RUNTIME) public @interface MappedSuperclass

Declares a class which is not itself an entity, but whose mappings are inherited by the entities which extend it.

A mapped superclass is not a persistent type, and is not mapped to a database table.

The persistent fields and properties of a mapped superclass are declared and mapped using the same mapping annotations used to map entity classes. However, these mappings are interpreted in the context of each entity class which inherits the mapped superclass, since the mapped superclass itself has no table to map.

Mapping information may be overridden in each such subclass using the AttributeOverride and AssociationOverride annotations or corresponding XML elements.

Example: Concrete class as a mapped superclass

@MappedSuperclass
public class Employee {

    @Id
    protected Integer empId;
    @Version
    protected Integer version;
    @ManyToOne
    @JoinColumn(name = "ADDR")
    protected Address address;

    public Integer getEmpId() { ... }
    public void setEmpId(Integer id) { ... }
    public Address getAddress() { ... }
    public void setAddress(Address addr) { ... }
}

// Default table is FTEMPLOYEE table
@Entity
public class FTEmployee extends Employee {

    // Inherited empId field mapped to FTEMPLOYEE.EMPID
    // Inherited version field mapped to FTEMPLOYEE.VERSION
    // Inherited address field mapped to FTEMPLOYEE.ADDR fk

    // Defaults to FTEMPLOYEE.SALARY
    protected Integer salary;

    public FTEmployee() {}

    public Integer getSalary() { ... }
    public void setSalary(Integer salary) { ... }
}

@Entity @Table(name = "PT_EMP")
@AssociationOverride(
    name = "address",
    joinColumns = @JoinColumn(name = "ADDR_ID"))
public class PartTimeEmployee extends Employee {

    // Inherited empId field mapped to PT_EMP.EMPID
    // Inherited version field mapped to PT_EMP.VERSION
    // address field mapping overridden to PT_EMP.ADDR_ID fk

    @Column(name = "WAGE")
    protected Float hourlyWage;

    public PartTimeEmployee() {}

    public Float getHourlyWage() { ... }
    public void setHourlyWage(Float wage) { ... }
}

Since:

1.0

See Also:

Annotation Interface MappedSuperclass