@Mutable

Use @Mutable on a @Basic mapping to specify if the value of a complex field type can be changed (or not changed) instead of being replaced. Mutable mappings may affect the performance of change tracking; attribute change tracking can only be weaved with non-mutable mappings.

Annotation Elements

Table 2-33 describes this annotation's elements.

Table 2-33 @Mutable Annotation Elements

Annotation Element	Description	Default
`boolean value`	(Optional) Specify if the mapping is mutable.	true

Usage

Most basic types (such as int, long, float, double, String, and BigDecimal) are not mutable.

By default, Date and Calendar types are assumed to be not mutable. To make these types mutable, use the @Mutable annotation. You can also use the global persistence property eclipselink.temporal.mutable to set the mappings as mutable.

By default, serialized types are assumed to be mutable. You can set the @Mutable annotation to false to make these types not mutable.

You can also configure mutable mappings for Date and Calendar fields in the persistence unit in the persistence.xml file.

Examples

Example 2-65 shows how to use the @Mutable annotation to specify Employee field hireDate.

Example 2-65 Using @Mutable Annotation

@Entity
public class Employee implements Serializable {

    ...

    @Temporal(DATE)
    @Mutable
    public Calendar getHireDate() {
        return hireDate;
    }

..
}

Example 2-66 shows how to configure mutable mappings in the persistence unit persistence.xml file or by importing a property map.

Example 2-66 Specifying Mutable Mappings in persistence.xml

Using persistence.xml file:

<property name="eclipselink.temporal.mutable" value="true"/>

Using property map:

import org.eclipse.persistence.config.PersistenceUnitProperties;
propertiesMap.put(PersistenceUnitProperties.TEMPORAL_MUTABLE, "false");

See Also

For more information, see:

"Mapping Annotations"