Custom Storing Behavior
Implementing the PersistenceEagerStoringFieldEvaluator
interface allows you to handle the eager/lazy storing behavior of any known member.
The default implementation of the EclipseStore engine threads all fields as lazy storing.
See Lazy and Eager Storing for details on lazy and eager storing.
The PersistenceEagerStoringFieldEvaluator
has only one method to be implemented: public boolean isEagerStoring(Class<?> t, Field u)
return true if the field has to be eager, otherwise return false.
public class CustomEagerStoringFieldEvaluator
implements PersistenceEagerStoringFieldEvaluator
{
@Override
public boolean isEagerStoring(Class<?> clazz, Field field)
{
if(clazz == MyClass.class && field.getName().equals("eagerField"))
{
return true;
}
return false;
}
}
To register the customized PersistenceEagerStoringFieldEvaluator
add it using the org.eclipse.persistence.types.PersistenceFoundation.setReferenceFieldEagerEvaluator(PersistenceEagerStoringFieldEvaluator)
method during the storage initialization.
NioFileSystem fileSystem = NioFileSystem.New();
EmbeddedStorageManager storage = EmbeddedStorage
.Foundation(fileSystem.ensureDirectoryPath(WORKINGDIR))
.onConnectionFoundation(f ->
{
f.setReferenceFieldEagerEvaluator(new CustomEagerStoringFieldEvaluator());
})
.start(ROOT)
;
The full code for the example is on GitHub. |