Hibernate : How override an attribute from mapped super class
The generic entity, super class:
@MappedSuperclass
public abstract class GenericEntity {
private Integer id;
public Integer getId() {return id;}
public void setId(Integer id) {this.id = id;}
}
The pojo:
@Entity
@Table(name = "POJO_ONE")
@SequenceGenerator(name = "HB_SEQ_POJO_ONE", sequenceName = "SEQ_POJO_ONE", allocationSize = 1)
public class PojoOne extends GenericEntity {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "HB_SEQ_POJO_ONE")
@Column(name = "ID")
@AttributeOverride(name = "id", column = @Column(name = "ID"))
private Integer id;
@Override
public Integer getId() {return id;}
}
I try to use thoses annotations : @AttributeOverride, @Id, ... but It doesn't work. Can you help me? I want to override the attribute "id" to specify another column name and a sequence by pojo/table. What is the best way to do that?
Solution 1:
Try this, instead
@MappedSuperclass
public abstract class GenericEntity {
protected Integer id;
...
public Integer getId() {return id;}
public void setId(Integer id) {this.id = id;}
}
@Entity
@Table(name = "POJO_ONE")
@SequenceGenerator(name = "HB_SEQ_POJO_ONE", sequenceName = "SEQ_POJO_ONE", allocationSize = 1)
@AttributeOverride(name = "id", column = @Column(name = "ID"))
public class PojoOne extends GenericEntity {
// we should not define id here again
...
@Override
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "HB_SEQ_POJO_ONE")
public Integer getId() {return id;}
}
Solution 2:
Why don't you annotate the id
of GenericEntity with @Id
?
You also should not redefine id
but put the @AttributeOverride(name = "id", column = @Column(name = "ID"))
on the class rather than a field.
Edit:
We're using this in our base class (package.OurTableGenerator
is our own implementation):
@GeneratedValue ( generator = "ourTableGenerator", strategy = GenerationType.TABLE )
@GenericGenerator ( name = "ourTableGenerator", strategy = "package.OurTableGenerator",
parameters = { @Parameter ( name = OurTableGenerator.TABLE_PARAM, value = "t_sequence" ),
@Parameter ( name = OurTableGenerator.SEGMENT_COLUMN_PARAM, value = "c_entity" ),
@Parameter ( name = OurTableGenerator.VALUE_COLUMN_PARAM, value = "c_nextHi" ),
@Parameter ( name = OurTableGenerator.INCREMENT_SIZE_COLUMN_PARAM, value = "c_blocksize" ) } )
@Id
@Column(name = "c_uid")
private Long uid;
This let's us specify a differenc block size and sequence per entity/table.
For your own table generator you could subclass org.hibernate.id.TableGenerator
.