Interface EntityManager


public interface EntityManager
Interface used to interact with the persistence context.

An EntityManager instance is associated with a persistence context. A persistence context is a set of entity instances in which for any persistent entity identity there is a unique entity instance. Within the persistence context, the entity instances and their lifecycle are managed. The EntityManager API is used to create and remove persistent entity instances, to find entities by their primary key, and to query over entities.

The set of entities that can be managed by a given EntityManager instance is defined by a persistence unit. A persistence unit defines the set of all classes that are related or grouped by the application, and which must be colocated in their mapping to a single database.

Since:
Java Persistence 1.0
See Also:
  • Method Details

    • persist

      void persist(Object entity)
      Make an instance managed and persistent.
      Parameters:
      entity - entity instance
      Throws:
      EntityExistsException - if the entity already exists. (If the entity already exists, the EntityExistsException may be thrown when the persist operation is invoked, or the EntityExistsException or another PersistenceException may be thrown at flush or commit time.)
      IllegalArgumentException - if the instance is not an entity
      TransactionRequiredException - if there is no transaction when invoked on a container-managed entity manager of that is of type PersistenceContextType.TRANSACTION
    • merge

      <T> T merge(T entity)
      Merge the state of the given entity into the current persistence context.
      Parameters:
      entity - entity instance
      Returns:
      the managed instance that the state was merged to
      Throws:
      IllegalArgumentException - if instance is not an entity or is a removed entity
      TransactionRequiredException - if there is no transaction when invoked on a container-managed entity manager of that is of type PersistenceContextType.TRANSACTION
    • remove

      void remove(Object entity)
      Remove the entity instance.
      Parameters:
      entity - entity instance
      Throws:
      IllegalArgumentException - if the instance is not an entity or is a detached entity
      TransactionRequiredException - if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION and there is no transaction
    • find

      <T> T find(Class<T> entityClass, Object primaryKey)
      Find by primary key. Search for an entity of the specified class and primary key. If the entity instance is contained in the persistence context, it is returned from there.
      Parameters:
      entityClass - entity class
      primaryKey - primary key
      Returns:
      the found entity instance or null if the entity does not exist
      Throws:
      IllegalArgumentException - if the first argument does not denote an entity type or the second argument is is not a valid type for that entity's primary key or is null
    • find

      <T> T find(Class<T> entityClass, Object primaryKey, Map<String,Object> properties)
      Find by primary key, using the specified properties. Search for an entity of the specified class and primary key. If the entity instance is contained in the persistence context, it is returned from there. If a vendor-specific property or hint is not recognized, it is silently ignored.
      Parameters:
      entityClass - entity class
      primaryKey - primary key
      properties - standard and vendor-specific properties and hints
      Returns:
      the found entity instance or null if the entity does not exist
      Throws:
      IllegalArgumentException - if the first argument does not denote an entity type or the second argument is is not a valid type for that entity's primary key or is null
      Since:
      Java Persistence 2.0
    • find

      <T> T find(Class<T> entityClass, Object primaryKey, LockModeType lockMode)
      Find by primary key and lock. Search for an entity of the specified class and primary key and lock it with respect to the specified lock type. If the entity instance is contained in the persistence context, it is returned from there, and the effect of this method is the same as if the lock method had been called on the entity.

      If the entity is found within the persistence context and the lock mode type is pessimistic and the entity has a version attribute, the persistence provider must perform optimistic version checks when obtaining the database lock. If these checks fail, the OptimisticLockException will be thrown.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback
      Parameters:
      entityClass - entity class
      primaryKey - primary key
      lockMode - lock mode
      Returns:
      the found entity instance or null if the entity does not exist
      Throws:
      IllegalArgumentException - if the first argument does not denote an entity type or the second argument is not a valid type for that entity's primary key or is null
      TransactionRequiredException - if there is no transaction and a lock mode other than NONE is specified or if invoked on an entity manager which has not been joined to the current transaction and a lock mode other than NONE is specified
      OptimisticLockException - if the optimistic version check fails
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
      Since:
      Java Persistence 2.0
    • find

      <T> T find(Class<T> entityClass, Object primaryKey, LockModeType lockMode, Map<String,Object> properties)
      Find by primary key and lock, using the specified properties. Search for an entity of the specified class and primary key and lock it with respect to the specified lock type. If the entity instance is contained in the persistence context, it is returned from there.

      If the entity is found within the persistence context and the lock mode type is pessimistic and the entity has a version attribute, the persistence provider must perform optimistic version checks when obtaining the database lock. If these checks fail, the OptimisticLockException will be thrown.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback

      If a vendor-specific property or hint is not recognized, it is silently ignored.

      Portable applications should not rely on the standard timeout hint. Depending on the database in use and the locking mechanisms used by the provider, the hint may or may not be observed.

      Parameters:
      entityClass - entity class
      primaryKey - primary key
      lockMode - lock mode
      properties - standard and vendor-specific properties and hints
      Returns:
      the found entity instance or null if the entity does not exist
      Throws:
      IllegalArgumentException - if the first argument does not denote an entity type or the second argument is not a valid type for that entity's primary key or is null
      TransactionRequiredException - if there is no transaction and a lock mode other than NONE is specified or if invoked on an entity manager which has not been joined to the current transaction and a lock mode other than NONE is specified
      OptimisticLockException - if the optimistic version check fails
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
      Since:
      Java Persistence 2.0
    • getReference

      <T> T getReference(Class<T> entityClass, Object primaryKey)
      Get an instance, whose state may be lazily fetched. If the requested instance does not exist in the database, the EntityNotFoundException is thrown when the instance state is first accessed. (The persistence provider runtime is permitted to throw the EntityNotFoundException when getReference is called.) The application should not expect that the instance state will be available upon detachment, unless it was accessed by the application while the entity manager was open.
      Parameters:
      entityClass - entity class
      primaryKey - primary key
      Returns:
      the found entity instance
      Throws:
      IllegalArgumentException - if the first argument does not denote an entity type or the second argument is not a valid type for that entity's primary key or is null
      EntityNotFoundException - if the entity state cannot be accessed
    • flush

      void flush()
      Synchronize the persistence context to the underlying database.
      Throws:
      TransactionRequiredException - if there is no transaction or if the entity manager has not been joined to the current transaction
      PersistenceException - if the flush fails
    • setFlushMode

      void setFlushMode(FlushModeType flushMode)
      Set the flush mode that applies to all objects contained in the persistence context.
      Parameters:
      flushMode - flush mode
    • getFlushMode

      FlushModeType getFlushMode()
      Get the flush mode that applies to all objects contained in the persistence context.
      Returns:
      flushMode
    • lock

      void lock(Object entity, LockModeType lockMode)
      Lock an entity instance that is contained in the persistence context with the specified lock mode type.

      If a pessimistic lock mode type is specified and the entity contains a version attribute, the persistence provider must also perform optimistic version checks when obtaining the database lock. If these checks fail, the OptimisticLockException will be thrown.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback
      Parameters:
      entity - entity instance
      lockMode - lock mode
      Throws:
      IllegalArgumentException - if the instance is not an entity or is a detached entity
      TransactionRequiredException - if there is no transaction or if invoked on an entity manager which has not been joined to the current transaction
      EntityNotFoundException - if the entity does not exist in the database when pessimistic locking is performed
      OptimisticLockException - if the optimistic version check fails
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
    • lock

      void lock(Object entity, LockModeType lockMode, Map<String,Object> properties)
      Lock an entity instance that is contained in the persistence context with the specified lock mode type and with specified properties.

      If a pessimistic lock mode type is specified and the entity contains a version attribute, the persistence provider must also perform optimistic version checks when obtaining the database lock. If these checks fail, the OptimisticLockException will be thrown.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback

      If a vendor-specific property or hint is not recognized, it is silently ignored.

      Portable applications should not rely on the standard timeout hint. Depending on the database in use and the locking mechanisms used by the provider, the hint may or may not be observed.

      Parameters:
      entity - entity instance
      lockMode - lock mode
      properties - standard and vendor-specific properties and hints
      Throws:
      IllegalArgumentException - if the instance is not an entity or is a detached entity
      TransactionRequiredException - if there is no transaction or if invoked on an entity manager which has not been joined to the current transaction
      EntityNotFoundException - if the entity does not exist in the database when pessimistic locking is performed
      OptimisticLockException - if the optimistic version check fails
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
      Since:
      Java Persistence 2.0
    • refresh

      void refresh(Object entity)
      Refresh the state of the instance from the database, overwriting changes made to the entity, if any.
      Parameters:
      entity - entity instance
      Throws:
      IllegalArgumentException - if the instance is not an entity or the entity is not managed
      TransactionRequiredException - if there is no transaction when invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION
      EntityNotFoundException - if the entity no longer exists in the database
    • refresh

      void refresh(Object entity, Map<String,Object> properties)
      Refresh the state of the instance from the database, using the specified properties, and overwriting changes made to the entity, if any.

      If a vendor-specific property or hint is not recognized, it is silently ignored.

      Parameters:
      entity - entity instance
      properties - standard and vendor-specific properties and hints
      Throws:
      IllegalArgumentException - if the instance is not an entity or the entity is not managed
      TransactionRequiredException - if there is no transaction when invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION
      EntityNotFoundException - if the entity no longer exists in the database
      Since:
      Java Persistence 2.0
    • refresh

      void refresh(Object entity, LockModeType lockMode)
      Refresh the state of the instance from the database, overwriting changes made to the entity, if any, and lock it with respect to given lock mode type.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback.
      Parameters:
      entity - entity instance
      lockMode - lock mode
      Throws:
      IllegalArgumentException - if the instance is not an entity or the entity is not managed
      TransactionRequiredException - if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION when there is no transaction; if invoked on an extended entity manager when there is no transaction and a lock mode other than NONE has been specified; or if invoked on an extended entity manager that has not been joined to the current transaction and a lock mode other than NONE has been specified
      EntityNotFoundException - if the entity no longer exists in the database
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
      Since:
      Java Persistence 2.0
    • refresh

      void refresh(Object entity, LockModeType lockMode, Map<String,Object> properties)
      Refresh the state of the instance from the database, overwriting changes made to the entity, if any, and lock it with respect to given lock mode type and with specified properties.

      If the lock mode type is pessimistic and the entity instance is found but cannot be locked:

      • the PessimisticLockException will be thrown if the database locking failure causes transaction-level rollback
      • the LockTimeoutException will be thrown if the database locking failure causes only statement-level rollback

      If a vendor-specific property or hint is not recognized, it is silently ignored.

      Portable applications should not rely on the standard timeout hint. Depending on the database in use and the locking mechanisms used by the provider, the hint may or may not be observed.

      Parameters:
      entity - entity instance
      lockMode - lock mode
      properties - standard and vendor-specific properties and hints
      Throws:
      IllegalArgumentException - if the instance is not an entity or the entity is not managed
      TransactionRequiredException - if invoked on a container-managed entity manager of type PersistenceContextType.TRANSACTION when there is no transaction; if invoked on an extended entity manager when there is no transaction and a lock mode other than NONE has been specified; or if invoked on an extended entity manager that has not been joined to the current transaction and a lock mode other than NONE has been specified
      EntityNotFoundException - if the entity no longer exists in the database
      PessimisticLockException - if pessimistic locking fails and the transaction is rolled back
      LockTimeoutException - if pessimistic locking fails and only the statement is rolled back
      PersistenceException - if an unsupported lock call is made
      Since:
      Java Persistence 2.0
    • clear

      void clear()
      Clear the persistence context, causing all managed entities to become detached. Changes made to entities that have not been flushed to the database will not be persisted.
    • detach

      void detach(Object entity)
      Remove the given entity from the persistence context, causing a managed entity to become detached. Unflushed changes made to the entity if any (including removal of the entity), will not be synchronized to the database. Entities which previously referenced the detached entity will continue to reference it.
      Parameters:
      entity - entity instance
      Throws:
      IllegalArgumentException - if the instance is not an entity
      Since:
      Java Persistence 2.0
    • contains

      boolean contains(Object entity)
      Check if the instance is a managed entity instance belonging to the current persistence context.
      Parameters:
      entity - entity instance
      Returns:
      boolean indicating if entity is in persistence context
      Throws:
      IllegalArgumentException - if not an entity
    • getLockMode

      LockModeType getLockMode(Object entity)
      Get the current lock mode for the entity instance.
      Parameters:
      entity - entity instance
      Returns:
      lock mode
      Throws:
      TransactionRequiredException - if there is no transaction or if the entity manager has not been joined to the current transaction
      IllegalArgumentException - if the instance is not a managed entity and a transaction is active
      Since:
      Java Persistence 2.0
    • setProperty

      void setProperty(String propertyName, Object value)
      Set an entity manager property or hint. If a vendor-specific property or hint is not recognized, it is silently ignored.
      Parameters:
      propertyName - name of property or hint
      value - value for property or hint
      Throws:
      IllegalArgumentException - if the second argument is not valid for the implementation
      Since:
      Java Persistence 2.0
    • getProperties

      Map<String,Object> getProperties()
      Get the properties and hints and associated values that are in effect for the entity manager. Changing the contents of the map does not change the configuration in effect.
      Returns:
      map of properties and hints in effect for entity manager
      Since:
      Java Persistence 2.0
    • createQuery

      Query createQuery(String qlString)
      Create an instance of Query for executing a Java Persistence query language statement.
      Parameters:
      qlString - a Java Persistence query string
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if the query string is found to be invalid
    • createQuery

      <T> TypedQuery<T> createQuery(CriteriaQuery<T> criteriaQuery)
      Create an instance of TypedQuery for executing a criteria query.
      Parameters:
      criteriaQuery - a criteria query object
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if the criteria query is found to be invalid
      Since:
      Java Persistence 2.0
    • createQuery

      Query createQuery(CriteriaUpdate updateQuery)
      Create an instance of Query for executing a criteria update query.
      Parameters:
      updateQuery - a criteria update query object
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if the update query is found to be invalid
      Since:
      Java Persistence 2.1
    • createQuery

      Query createQuery(CriteriaDelete deleteQuery)
      Create an instance of Query for executing a criteria delete query.
      Parameters:
      deleteQuery - a criteria delete query object
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if the delete query is found to be invalid
      Since:
      Java Persistence 2.1
    • createQuery

      <T> TypedQuery<T> createQuery(String qlString, Class<T> resultClass)
      Create an instance of TypedQuery for executing a Java Persistence query language statement. The select list of the query must contain only a single item, which must be assignable to the type specified by the resultClass argument.
      Parameters:
      qlString - a Java Persistence query string
      resultClass - the type of the query result
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if the query string is found to be invalid or if the query result is found to not be assignable to the specified type
      Since:
      Java Persistence 2.0
    • createNamedQuery

      Query createNamedQuery(String name)
      Create an instance of Query for executing a named query (in the Java Persistence query language or in native SQL).
      Parameters:
      name - the name of a query defined in metadata
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if a query has not been defined with the given name or if the query string is found to be invalid
    • createNamedQuery

      <T> TypedQuery<T> createNamedQuery(String name, Class<T> resultClass)
      Create an instance of TypedQuery for executing a Java Persistence query language named query. The select list of the query must contain only a single item, which must be assignable to the type specified by the resultClass argument.
      Parameters:
      name - the name of a query defined in metadata
      resultClass - the type of the query result
      Returns:
      the new query instance
      Throws:
      IllegalArgumentException - if a query has not been defined with the given name or if the query string is found to be invalid or if the query result is found to not be assignable to the specified type
      Since:
      Java Persistence 2.0
    • createNativeQuery

      Query createNativeQuery(String sqlString)
      Create an instance of Query for executing a native SQL statement, e.g., for update or delete. If the query is not an update or delete query, query execution will result in each row of the SQL result being returned as a result of type Object[] (or a result of type Object if there is only one column in the select list.) Column values are returned in the order of their appearance in the select list and default JDBC type mappings are applied.
      Parameters:
      sqlString - a native SQL query string
      Returns:
      the new query instance
    • createNativeQuery

      Query createNativeQuery(String sqlString, Class resultClass)
      Create an instance of Query for executing a native SQL query.
      Parameters:
      sqlString - a native SQL query string
      resultClass - the class of the resulting instance(s)
      Returns:
      the new query instance
    • createNativeQuery

      Query createNativeQuery(String sqlString, String resultSetMapping)
      Create an instance of Query for executing a native SQL query.
      Parameters:
      sqlString - a native SQL query string
      resultSetMapping - the name of the result set mapping
      Returns:
      the new query instance
    • createNamedStoredProcedureQuery

      StoredProcedureQuery createNamedStoredProcedureQuery(String name)
      Create an instance of StoredProcedureQuery for executing a stored procedure in the database.

      Parameters must be registered before the stored procedure can be executed.

      If the stored procedure returns one or more result sets, any result set will be returned as a list of type Object[].

      Parameters:
      name - name assigned to the stored procedure query in metadata
      Returns:
      the new stored procedure query instance
      Throws:
      IllegalArgumentException - if a query has not been defined with the given name
      Since:
      Java Persistence 2.1
    • createStoredProcedureQuery

      StoredProcedureQuery createStoredProcedureQuery(String procedureName)
      Create an instance of StoredProcedureQuery for executing a stored procedure in the database.

      Parameters must be registered before the stored procedure can be executed.

      If the stored procedure returns one or more result sets, any result set will be returned as a list of type Object[].

      Parameters:
      procedureName - name of the stored procedure in the database
      Returns:
      the new stored procedure query instance
      Throws:
      IllegalArgumentException - if a stored procedure of the given name does not exist (or the query execution will fail)
      Since:
      Java Persistence 2.1
    • createStoredProcedureQuery

      StoredProcedureQuery createStoredProcedureQuery(String procedureName, Class... resultClasses)
      Create an instance of StoredProcedureQuery for executing a stored procedure in the database.

      Parameters must be registered before the stored procedure can be executed.

      The resultClass arguments must be specified in the order in which the result sets will be returned by the stored procedure invocation.

      Parameters:
      procedureName - name of the stored procedure in the database
      resultClasses - classes to which the result sets produced by the stored procedure are to be mapped
      Returns:
      the new stored procedure query instance
      Throws:
      IllegalArgumentException - if a stored procedure of the given name does not exist (or the query execution will fail)
      Since:
      Java Persistence 2.1
    • createStoredProcedureQuery

      StoredProcedureQuery createStoredProcedureQuery(String procedureName, String... resultSetMappings)
      Create an instance of StoredProcedureQuery for executing a stored procedure in the database.

      Parameters must be registered before the stored procedure can be executed.

      The resultSetMapping arguments must be specified in the order in which the result sets will be returned by the stored procedure invocation.

      Parameters:
      procedureName - name of the stored procedure in the database
      resultSetMappings - the names of the result set mappings to be used in mapping result sets returned by the stored procedure
      Returns:
      the new stored procedure query instance
      Throws:
      IllegalArgumentException - if a stored procedure or result set mapping of the given name does not exist (or the query execution will fail)
    • joinTransaction

      void joinTransaction()
      Indicate to the entity manager that a JTA transaction is active and join the persistence context to it.

      This method should be called on a JTA application managed entity manager that was created outside the scope of the active transaction or on an entity manager of type SynchronizationType.UNSYNCHRONIZED to associate it with the current JTA transaction.

      Throws:
      TransactionRequiredException - if there is no transaction
    • isJoinedToTransaction

      boolean isJoinedToTransaction()
      Determine whether the entity manager is joined to the current transaction. Returns false if the entity manager is not joined to the current transaction or if no transaction is active
      Returns:
      boolean
      Since:
      Java Persistence 2.1
    • unwrap

      <T> T unwrap(Class<T> cls)
      Return an object of the specified type to allow access to the provider-specific API. If the provider's EntityManager implementation does not support the specified class, the PersistenceException is thrown.
      Parameters:
      cls - the class of the object to be returned. This is normally either the underlying EntityManager implementation class or an interface that it implements.
      Returns:
      an instance of the specified class
      Throws:
      PersistenceException - if the provider does not support the call
      Since:
      Java Persistence 2.0
    • getDelegate

      Object getDelegate()
      Return the underlying provider object for the EntityManager, if available. The result of this method is implementation specific.

      The unwrap method is to be preferred for new applications.

      Returns:
      underlying provider object for EntityManager
    • close

      void close()
      Close an application-managed entity manager. After the close method has been invoked, all methods on the EntityManager instance and any Query, TypedQuery, and StoredProcedureQuery objects obtained from it will throw the IllegalStateException except for getProperties, getTransaction, and isOpen (which will return false). If this method is called when the entity manager is joined to an active transaction, the persistence context remains managed until the transaction completes.
      Throws:
      IllegalStateException - if the entity manager is container-managed
    • isOpen

      boolean isOpen()
      Determine whether the entity manager is open.
      Returns:
      true until the entity manager has been closed
    • getTransaction

      EntityTransaction getTransaction()
      Return the resource-level EntityTransaction object. The EntityTransaction instance may be used serially to begin and commit multiple transactions.
      Returns:
      EntityTransaction instance
      Throws:
      IllegalStateException - if invoked on a JTA entity manager
    • getEntityManagerFactory

      EntityManagerFactory getEntityManagerFactory()
      Return the entity manager factory for the entity manager.
      Returns:
      EntityManagerFactory instance
      Throws:
      IllegalStateException - if the entity manager has been closed
      Since:
      Java Persistence 2.0
    • getCriteriaBuilder

      CriteriaBuilder getCriteriaBuilder()
      Return an instance of CriteriaBuilder for the creation of CriteriaQuery objects.
      Returns:
      CriteriaBuilder instance
      Throws:
      IllegalStateException - if the entity manager has been closed
      Since:
      Java Persistence 2.0
    • getMetamodel

      Metamodel getMetamodel()
      Return an instance of Metamodel interface for access to the metamodel of the persistence unit.
      Returns:
      Metamodel instance
      Throws:
      IllegalStateException - if the entity manager has been closed
      Since:
      Java Persistence 2.0
    • createEntityGraph

      <T> EntityGraph<T> createEntityGraph(Class<T> rootType)
      Return a mutable EntityGraph that can be used to dynamically create an EntityGraph.
      Parameters:
      rootType - class of entity graph
      Returns:
      entity graph
      Since:
      Java Persistence 2.1
    • createEntityGraph

      EntityGraph<?> createEntityGraph(String graphName)
      Return a mutable copy of the named EntityGraph. If there is no entity graph with the specified name, null is returned.
      Parameters:
      graphName - name of an entity graph
      Returns:
      entity graph
      Since:
      Java Persistence 2.1
    • getEntityGraph

      EntityGraph<?> getEntityGraph(String graphName)
      Return a named EntityGraph. The returned EntityGraph should be considered immutable.
      Parameters:
      graphName - name of an existing entity graph
      Returns:
      named entity graph
      Throws:
      IllegalArgumentException - if there is no EntityGraph of the given name
      Since:
      Java Persistence 2.1
    • getEntityGraphs

      <T> List<EntityGraph<? super T>> getEntityGraphs(Class<T> entityClass)
      Return all named EntityGraphs that have been defined for the provided class type.
      Parameters:
      entityClass - entity class
      Returns:
      list of all entity graphs defined for the entity
      Throws:
      IllegalArgumentException - if the class is not an entity
      Since:
      Java Persistence 2.1