Use @TypeConverter
to modify data values during the reading and writing of a mapped attribute.
Table 2-72 describes this annotation's elements.
Table 2-72 @TypeConverter Annotation Elements
Annotation Element | Description | Default |
---|---|---|
|
(Required) The |
none |
|
(Optional) The |
|
|
(Optional) The |
|
Footnote 1 The default is inferred from the type of the persistence field or property.
Each TypeConverter
must be uniquely named and can be defined at the class, field and property level and can be specified within an Entity, MappedSuperclass and Embeddable class. A TypeConverter
is always specified by using an @Convert
annotation
You can place a @TypeConverter
on a Basic
, BasicMap
or BasicCollection
mapping.
Oracle TopLink also includes @ObjectTypeConverter
and @StructConverter
converters.
Example 2-116 shows how to use the @TypeConverter
annotation to convert the Double
value stored in the database to a Float
value stored in the entity.
Example 2-116 Using the @TypeConverter Annotation
@Entity
public class Employee implements Serializable{
...
@TypeConverter (
name="doubleToFloat",
dataType=Double.class,
objectType=Float.class,
)
@Convert("doubleToFloat")
public Number getGradePointAverage() {
return gradePointAverage;
}
...
}
For more information, see: