Module jakarta.persistence

Package jakarta.persistence

Interface PersistenceUnitUtil

All Superinterfaces:

PersistenceUtil

public interface PersistenceUnitUtil
extends PersistenceUtil

Utility interface between the application and the persistence provider managing the persistence unit.

The methods of this interface should only be invoked on entity instances obtained from or managed by entity managers for this persistence unit or on new entity instances.

Since:

2.0

Method Summary

Modifier and Type	Method	Description
<T> Class<? extends T>	getClass(T entity)	Return the concrete entity class if the given entity belonging to the persistence unit and to an open persistence context.
Object	getIdentifier(Object entity)	Return the id of the entity.
Object	getVersion(Object entity)	Return the version of the entity.
boolean	isInstance(Object entity, Class<?> entityClass)	Return true if the given entity belonging to the persistence unit and to an open persistence context is an instance of the given entity class, or false otherwise.
<E> boolean	isLoaded(E entity, Attribute<? super E,?> attribute)	Determine the load state of a given persistent attribute of an entity belonging to the persistence unit.
boolean	isLoaded(Object entity)	Determine the load state of an entity belonging to the persistence unit.
boolean	isLoaded(Object entity, String attributeName)	Determine the load state of a given persistent attribute of an entity belonging to the persistence unit.
<E> void	load(E entity, Attribute<? super E,?> attribute)	Load the persistent value of a given persistent attribute of an entity belonging to the persistence unit and to an open persistence context.
void	load(Object entity)	Load the persistent state of an entity belonging to the persistence unit and to an open persistence context.
void	load(Object entity, String attributeName)	Load the persistent value of a given persistent attribute of an entity belonging to the persistence unit and to an open persistence context.

Method Details

isLoaded

boolean isLoaded(Object entity,
 String attributeName)

Determine the load state of a given persistent attribute of an entity belonging to the persistence unit.

Specified by:

isLoaded in interface PersistenceUtil

Parameters:

entity - entity instance containing the attribute

attributeName - name of attribute whose load state is to be determined

Returns:

false if entity's state has not been loaded or if the attribute state has not been loaded, else true

isLoaded

<E> boolean isLoaded(E entity,
 Attribute<? super E,?> attribute)

Determine the load state of a given persistent attribute of an entity belonging to the persistence unit.

Parameters:

entity - entity instance containing the attribute

attribute - attribute whose load state is to be determined

Returns:

false if entity's state has not been loaded or if the attribute state has not been loaded, else true

Since:

3.2

isLoaded

boolean isLoaded(Object entity)

Determine the load state of an entity belonging to the persistence unit. This method can be used to determine the load state of an entity passed as a reference. An entity is considered loaded if all attributes for which FetchType.EAGER has been specified have been loaded.

The isLoaded(Object, String) method should be used to determine the load state of an attribute. Not doing so might lead to unintended loading of state.

Specified by:

isLoaded in interface PersistenceUtil

Parameters:

entity - entity instance whose load state is to be determined

Returns:

false if the entity has not been loaded, else true

load

void load(Object entity,
 String attributeName)

Load the persistent value of a given persistent attribute of an entity belonging to the persistence unit and to an open persistence context. After this method returns, isLoaded(Object,String) must return true with the given entity instance and attribute.

Parameters:

entity - entity instance

attributeName - the name of the attribute to be loaded

Throws:

IllegalArgumentException - if the given object is not an instance of an entity class belonging to the persistence unit

PersistenceException - if the entity is not associated with an open persistence context or cannot be loaded from the database

Since:

3.2

load

<E> void load(E entity,
 Attribute<? super E,?> attribute)

Load the persistent value of a given persistent attribute of an entity belonging to the persistence unit and to an open persistence context. After this method returns, isLoaded(Object,Attribute) must return true with the given entity instance and attribute.

Parameters:

entity - entity instance to be loaded

attribute - the attribute to be loaded

Throws:

IllegalArgumentException - if the given object is not an instance of an entity class belonging to the persistence unit

PersistenceException - if the entity is not associated with an open persistence context or cannot be loaded from the database

Since:

3.2

load

void load(Object entity)

Load the persistent state of an entity belonging to the persistence unit and to an open persistence context. After this method returns, isLoaded(Object) must return true with the given entity instance.

Parameters:

entity - entity instance to be loaded

Throws:

IllegalArgumentException - if the given object is not an instance of an entity class belonging to the persistence unit

PersistenceException - if the entity is not associated with an open persistence context or cannot be loaded from the database

Since:

3.2

isInstance

boolean isInstance(Object entity,
 Class<?> entityClass)

Return true if the given entity belonging to the persistence unit and to an open persistence context is an instance of the given entity class, or false otherwise. This method may, but is not required to, load the given entity by side effect.

Parameters:

entity - entity instance

entityClass - an entity class belonging to the persistence unit

Throws:

IllegalArgumentException - if the given object is not an instance of an entity class belonging to the persistence unit or if the given class is not an entity class belonging to the persistence unit

PersistenceException - if the entity is not associated with an open persistence context or cannot be loaded from the database

Since:

3.2

getClass

<T> Class<? extends T> getClass(T entity)

Return the concrete entity class if the given entity belonging to the persistence unit and to an open persistence context. This method may, but is not required to, load the given entity by side effect.

Parameters:

entity - entity instance

Returns:

an entity class belonging to the persistence unit

Throws:

IllegalArgumentException - if the given object is not an instance of an entity class belonging to the persistence unit

PersistenceException - if the entity is not associated with an open persistence context or cannot be loaded from the database

Since:

3.2

getIdentifier

Object getIdentifier(Object entity)

Return the id of the entity. A generated id is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not yet have an id.

Parameters:

entity - entity instance

Returns:

id of the entity

Throws:

IllegalArgumentException - if the object is found not to be an entity

getVersion

Object getVersion(Object entity)

Return the version of the entity. A generated version is not guaranteed to be available until after the database insert has occurred. Returns null if the entity does not yet have an id.

Parameters:

entity - entity instance

Returns:

id of the entity

Throws:

IllegalArgumentException - if the object is found not to be an entity

Since:

3.2