Package org.hibernate

Interface NaturalIdLoadAccess<T>

All Known Implementing Classes:

NaturalIdLoadAccessImpl

public interface NaturalIdLoadAccess<T>

Loads an entity by its natural identifier.

This is a generic form of load-by-natural-id covering both a single attribute and multiple attributes as the natural-id. For natural-ids defined by a single attribute, SimpleNaturalIdLoadAccess offers simplified access.

See Also:

NaturalId, Session.byNaturalId(java.lang.String)

Method Summary

Modifier and Type	Method	Description
T	getReference()	Return the persistent instance with the natural id value(s) defined by the call(s) to using(java.lang.String, java.lang.Object).
T	load()	Return the persistent instance with the natural id value(s) defined by the call(s) to using(java.lang.String, java.lang.Object), or null if there is no such persistent instance.
Optional<T>	loadOptional()	Same semantic as load() except that here Optional is returned to handle nullability.
NaturalIdLoadAccess<T>	setSynchronizationEnabled(boolean enabled)	For entities with mutable natural ids, should natural ids be synchronized prior to performing a lookup? The default, for correctness, is to synchronize.
NaturalIdLoadAccess<T>	using(Object... mappings)	Set multiple natural-id attribute values at once.
NaturalIdLoadAccess<T>	using(String attributeName, Object value)	Add a NaturalId attribute value.
NaturalIdLoadAccess<T>	with(LockOptions lockOptions)	Specify the LockOptions to use when retrieving the entity.

Method Detail

with

NaturalIdLoadAccess<T> with(LockOptions lockOptions)

Specify the LockOptions to use when retrieving the entity.

Parameters:

lockOptions - The lock options to use.

Returns:

this, for method chaining

using

NaturalIdLoadAccess<T> using(String attributeName,
                             Object value)

Add a NaturalId attribute value.

Parameters:

attributeName - The entity attribute name that is marked as a NaturalId

value - The value of the attribute

Returns:

this, for method chaining

using

NaturalIdLoadAccess<T> using(Object... mappings)

Set multiple natural-id attribute values at once. The passed array is expected to have an even number of elements, with the attribute name followed by its value, for example, using( "system", "matrix", "username", "neo" ).

Returns:

this, for method chaining

setSynchronizationEnabled

NaturalIdLoadAccess<T> setSynchronizationEnabled(boolean enabled)

For entities with mutable natural ids, should natural ids be synchronized prior to performing a lookup? The default, for correctness, is to synchronize.

Here "synchronization" means updating the natural id to primary key cross-reference maintained by the session. When enabled, prior to performing the lookup, Hibernate will check all entities of the given type associated with the session to see if any natural id values have changed and, if so, update the cross-reference. There is a performance penalty associated with this, so if it is completely certain the no natural id in play has changed, this setting can be disabled to circumvent that impact. Disabling this setting when natural id values have changed can result in incorrect results!

Parameters:

enabled - Should synchronization be performed? true indicates synchronization will be performed; false indicates it will be circumvented.

Returns:

this, for method chaining

getReference

T getReference()

Return the persistent instance with the natural id value(s) defined by the call(s) to using(java.lang.String, java.lang.Object). This method might return a proxied instance that is initialized on-demand, when a non-identifier method is accessed.

You should not use this method to determine if an instance exists; to check for existence, use load() instead. Use this only to retrieve an instance that you assume exists, where non-existence would be an actual error.

Returns:

the persistent instance or proxy

load

T load()

Return the persistent instance with the natural id value(s) defined by the call(s) to using(java.lang.String, java.lang.Object), or null if there is no such persistent instance. If the instance is already associated with the session, return that instance, initializing it if needed. This method never returns an uninitialized instance.

Returns:

The persistent instance or null

loadOptional

Optional<T> loadOptional()

Same semantic as load() except that here Optional is returned to handle nullability.

Returns:

The persistent instance, if one, wrapped in Optional