public interface EntityManager
 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.
Query, 
TypedQuery, 
CriteriaQuery, 
PersistenceContext| Modifier and Type | Method and Description | 
|---|---|
| void | clear()Clear the persistence context, causing all managed
 entities to become detached. | 
| void | close()Close an application-managed entity manager. | 
| boolean | contains(Object entity)Check if the instance is a managed entity instance belonging
 to the current persistence context. | 
| <T> EntityGraph<T> | createEntityGraph(Class<T> rootType)Return a mutable EntityGraph that can be used to dynamically create an EntityGraph. | 
| EntityGraph<?> | createEntityGraph(String graphName)Return a mutable copy of the named EntityGraph. | 
| Query | createNamedQuery(String name)Create an instance of  Queryfor executing a named query
 (in the Java Persistence query language or in native SQL). | 
| <T> TypedQuery<T> | createNamedQuery(String name,
                Class<T> resultClass)Create an instance of  TypedQueryfor executing a
 Java Persistence query language named query. | 
| StoredProcedureQuery | createNamedStoredProcedureQuery(String name)Create an instance of StoredProcedureQuery for executing a
 stored procedure in the database. | 
| Query | createNativeQuery(String sqlString)Create an instance of  Queryfor executing
 a native SQL statement, e.g., for update or delete. | 
| Query | createNativeQuery(String sqlString,
                 Class resultClass)Create an instance of  Queryfor executing
 a native SQL query. | 
| Query | createNativeQuery(String sqlString,
                 String resultSetMapping)Create an instance of  Queryfor executing
 a native SQL query. | 
| Query | createQuery(CriteriaDelete deleteQuery)Create an instance of Query for executing a criteria
 delete query. | 
| <T> TypedQuery<T> | createQuery(CriteriaQuery<T> criteriaQuery)Create an instance of  TypedQueryfor executing a
 criteria query. | 
| Query | createQuery(CriteriaUpdate updateQuery)Create an instance of Query for executing a criteria
 update query. | 
| Query | createQuery(String qlString)Create an instance of  Queryfor executing a
 Java Persistence query language statement. | 
| <T> TypedQuery<T> | createQuery(String qlString,
           Class<T> resultClass)Create an instance of  TypedQueryfor executing a
 Java Persistence query language statement. | 
| StoredProcedureQuery | createStoredProcedureQuery(String procedureName)Create an instance of StoredProcedureQuery for executing a
 stored procedure in the database. | 
| StoredProcedureQuery | createStoredProcedureQuery(String procedureName,
                          Class... resultClasses)Create an instance of StoredProcedureQuery for executing a
 stored procedure in the database. | 
| StoredProcedureQuery | createStoredProcedureQuery(String procedureName,
                          String... resultSetMappings)Create an instance of StoredProcedureQuery for executing a
 stored procedure in the database. | 
| void | detach(Object entity)Remove the given entity from the persistence context, causing
 a managed entity to become detached. | 
| <T> T | find(Class<T> entityClass,
    Object primaryKey)Find by primary key. | 
| <T> T | find(Class<T> entityClass,
    Object primaryKey,
    LockModeType lockMode)Find by primary key and lock. | 
| <T> T | find(Class<T> entityClass,
    Object primaryKey,
    LockModeType lockMode,
    Map<String,Object> properties)Find by primary key and lock, using the specified properties. | 
| <T> T | find(Class<T> entityClass,
    Object primaryKey,
    Map<String,Object> properties)Find by primary key, using the specified properties. | 
| void | flush()Synchronize the persistence context to the
 underlying database. | 
| CriteriaBuilder | getCriteriaBuilder()Return an instance of  CriteriaBuilderfor the creation ofCriteriaQueryobjects. | 
| Object | getDelegate()Return the underlying provider object for the  EntityManager,
 if available. | 
| EntityGraph<?> | getEntityGraph(String graphName)Return a named EntityGraph. | 
| <T> List<EntityGraph<? super T>> | getEntityGraphs(Class<T> entityClass)Return all named EntityGraphs that have been defined for the provided class type. | 
| EntityManagerFactory | getEntityManagerFactory()Return the entity manager factory for the entity manager. | 
| FlushModeType | getFlushMode()Get the flush mode that applies to all objects contained
 in the persistence context. | 
| LockModeType | getLockMode(Object entity)Get the current lock mode for the entity instance. | 
| Metamodel | getMetamodel()Return an instance of  Metamodelinterface for access to the
 metamodel of the persistence unit. | 
| Map<String,Object> | getProperties()Get the properties and hints and associated values that are in effect
 for the entity manager. | 
| <T> T | getReference(Class<T> entityClass,
            Object primaryKey)Get an instance, whose state may be lazily fetched. | 
| EntityTransaction | getTransaction()Return the resource-level  EntityTransactionobject. | 
| boolean | isJoinedToTransaction()Determine whether the entity manager is joined to the
 current transaction. | 
| boolean | isOpen()Determine whether the entity manager is open. | 
| void | joinTransaction()Indicate to the entity manager that a JTA transaction is
 active. | 
| void | lock(Object entity,
    LockModeType lockMode)Lock an entity instance that is contained in the persistence
 context with the specified lock mode type. | 
| 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. | 
| <T> T | merge(T entity)Merge the state of the given entity into the
 current persistence context. | 
| void | persist(Object entity)Make an instance managed and persistent. | 
| void | refresh(Object entity)Refresh the state of the instance from the database,
 overwriting changes made to the entity, if any. | 
| 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. | 
| 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. | 
| 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. | 
| void | remove(Object entity)Remove the entity instance. | 
| void | setFlushMode(FlushModeType flushMode)Set the flush mode that applies to all objects contained
 in the persistence context. | 
| void | setProperty(String propertyName,
           Object value)Set an entity manager property or hint. | 
| <T> T | unwrap(Class<T> cls)Return an object of the specified type to allow access to the
 provider-specific API. | 
void persist(Object entity)
entity - entity instanceEntityExistsException - 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
         entityTransactionRequiredException - if invoked on a
         container-managed entity manager of type
         PersistenceContextType.TRANSACTION and there is
         no transaction<T> T merge(T entity)
entity - entity instanceIllegalArgumentException - if instance is not an
         entity or is a removed entityTransactionRequiredException - if invoked on a
         container-managed entity manager of type
         PersistenceContextType.TRANSACTION and there is
         no transactionvoid remove(Object entity)
entity - entity instanceIllegalArgumentException - if the instance is not an
         entity or is a detached entityTransactionRequiredException - if invoked on a
         container-managed entity manager of type
         PersistenceContextType.TRANSACTION and there is
         no transaction<T> T find(Class<T> entityClass, Object primaryKey)
entityClass - entity classprimaryKey - primary keyIllegalArgumentException - if the first argument does
         not denote an entity type or the second argument is
         is not a valid type for that entitys primary key or
         is null<T> T find(Class<T> entityClass, Object primaryKey, Map<String,Object> properties)
entityClass - entity classprimaryKey - primary keyproperties - standard and vendor-specific properties
        and hintsIllegalArgumentException - if the first argument does
         not denote an entity type or the second argument is
         is not a valid type for that entitys primary key or
         is null<T> T find(Class<T> entityClass, Object primaryKey, LockModeType lockMode)
 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:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 LockTimeoutException will be thrown if the database
    locking failure causes only statement-level rollback
 entityClass - entity classprimaryKey - primary keylockMode - lock modeIllegalArgumentException - 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 nullTransactionRequiredException - if there is no
         transaction and a lock mode other than NONE is
         specifiedOptimisticLockException - if the optimistic version
         check failsPessimisticLockException - if pessimistic locking
         fails and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is made<T> T find(Class<T> entityClass, Object primaryKey, LockModeType lockMode, Map<String,Object> properties)
 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:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 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.
entityClass - entity classprimaryKey - primary keylockMode - lock modeproperties - standard and vendor-specific properties
        and hintsIllegalArgumentException - 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 nullTransactionRequiredException - if there is no
         transaction and a lock mode other than NONE is
         specifiedOptimisticLockException - if the optimistic version
         check failsPessimisticLockException - if pessimistic locking
         fails and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is made<T> T getReference(Class<T> entityClass, Object primaryKey)
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.entityClass - entity classprimaryKey - primary keyIllegalArgumentException - if the first argument does
         not denote an entity type or the second argument is
         not a valid type for that entitys primary key or
         is nullEntityNotFoundException - if the entity state
         cannot be accessedvoid flush()
TransactionRequiredException - if there is
         no transactionPersistenceException - if the flush failsvoid setFlushMode(FlushModeType flushMode)
flushMode - flush modeFlushModeType getFlushMode()
void lock(Object entity, LockModeType lockMode)
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:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 LockTimeoutException will be thrown if the database
    locking failure causes only statement-level rollback
 entity - entity instancelockMode - lock modeIllegalArgumentException - if the instance is not an
         entity or is a detached entityTransactionRequiredException - if there is no
         transactionEntityNotFoundException - if the entity does not exist
         in the database when pessimistic locking is
         performedOptimisticLockException - if the optimistic version
         check failsPessimisticLockException - if pessimistic locking fails
         and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is madevoid lock(Object entity, LockModeType lockMode, Map<String,Object> 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:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 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.
entity - entity instancelockMode - lock modeproperties - standard and vendor-specific properties
        and hintsIllegalArgumentException - if the instance is not an
         entity or is a detached entityTransactionRequiredException - if there is no
         transactionEntityNotFoundException - if the entity does not exist
         in the database when pessimistic locking is
         performedOptimisticLockException - if the optimistic version
         check failsPessimisticLockException - if pessimistic locking fails
         and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is madevoid refresh(Object entity)
entity - entity instanceIllegalArgumentException - if the instance is not
         an entity or the entity is not managedTransactionRequiredException - if invoked on a
         container-managed entity manager of type
         PersistenceContextType.TRANSACTION and there is
         no transactionEntityNotFoundException - if the entity no longer
         exists in the databasevoid refresh(Object entity, Map<String,Object> properties)
If a vendor-specific property or hint is not recognized, it is silently ignored.
entity - entity instanceproperties - standard and vendor-specific properties
        and hintsIllegalArgumentException - if the instance is not
         an entity or the entity is not managedTransactionRequiredException - if invoked on a
         container-managed entity manager of type
         PersistenceContextType.TRANSACTION and there is
         no transactionEntityNotFoundException - if the entity no longer
         exists in the databasevoid refresh(Object entity, LockModeType lockMode)
If the lock mode type is pessimistic and the entity instance is found but cannot be locked:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 LockTimeoutException will be thrown if the
    database locking failure causes only statement-level
    rollback.
 entity - entity instancelockMode - lock modeIllegalArgumentException - if the instance is not
         an entity or the entity is not managedTransactionRequiredException - if there is no
         transaction and if invoked on a container-managed
         EntityManager instance with
         PersistenceContextType.TRANSACTION or with a lock mode
         other than NONEEntityNotFoundException - if the entity no longer exists
         in the databasePessimisticLockException - if pessimistic locking fails
         and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is madevoid refresh(Object entity, LockModeType lockMode, Map<String,Object> properties)
If the lock mode type is pessimistic and the entity instance is found but cannot be locked:
PessimisticLockException will be thrown if the database
    locking failure causes transaction-level rollback
 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.
entity - entity instancelockMode - lock modeproperties - standard and vendor-specific properties
        and hintsIllegalArgumentException - if the instance is not
         an entity or the entity is not managedTransactionRequiredException - if there is no
         transaction and if invoked on a container-managed
         EntityManager instance with
         PersistenceContextType.TRANSACTION or with a lock mode
         other than NONEEntityNotFoundException - if the entity no longer exists
         in the databasePessimisticLockException - if pessimistic locking fails
         and the transaction is rolled backLockTimeoutException - if pessimistic locking fails and
         only the statement is rolled backPersistenceException - if an unsupported lock call
         is madevoid clear()
void detach(Object entity)
entity - entity instanceIllegalArgumentException - if the instance is not an
         entityboolean contains(Object entity)
entity - entity instanceIllegalArgumentException - if not an entityLockModeType getLockMode(Object entity)
entity - entity instanceTransactionRequiredException - if there is no
         transactionIllegalArgumentException - if the instance is not a
         managed entity and a transaction is activevoid setProperty(String propertyName, Object value)
propertyName - name of property or hintvalue - value for property or hintIllegalArgumentException - if the second argument is
         not valid for the implementationMap<String,Object> getProperties()
Query createQuery(String qlString)
Query for executing a
 Java Persistence query language statement.qlString - a Java Persistence query stringIllegalArgumentException - if the query string is
         found to be invalid<T> TypedQuery<T> createQuery(CriteriaQuery<T> criteriaQuery)
TypedQuery for executing a
 criteria query.criteriaQuery - a criteria query objectIllegalArgumentException - if the criteria query is
         found to be invalidQuery createQuery(CriteriaUpdate updateQuery)
updateQuery - a criteria update query objectIllegalArgumentException - if the update query is found to be invalidQuery createQuery(CriteriaDelete deleteQuery)
deleteQuery - a criteria delete query objectIllegalArgumentException - if the delete query isfound to be invalid<T> TypedQuery<T> createQuery(String qlString, Class<T> resultClass)
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.qlString - a Java Persistence query stringresultClass - the type of the query resultIllegalArgumentException - if the query string is found
         to be invalid or if the query result is found to
         not be assignable to the specified typeQuery createNamedQuery(String name)
Query for executing a named query
 (in the Java Persistence query language or in native SQL).name - the name of a query defined in metadataIllegalArgumentException - if a query has not been
         defined with the given name or if the query string is
         found to be invalid<T> TypedQuery<T> createNamedQuery(String name, Class<T> resultClass)
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.name - the name of a query defined in metadataresultClass - the type of the query resultIllegalArgumentException - 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 typeQuery createNativeQuery(String sqlString)
Query for executing
 a native SQL statement, e.g., for update or delete.sqlString - a native SQL query stringQuery createNativeQuery(String sqlString, Class resultClass)
Query for executing
 a native SQL query.sqlString - a native SQL query stringresultClass - the class of the resulting instance(s)Query createNativeQuery(String sqlString, String resultSetMapping)
Query for executing
 a native SQL query.sqlString - a native SQL query stringresultSetMapping - the name of the result set mappingStoredProcedureQuery createNamedStoredProcedureQuery(String name)
name - name assigned to the stored procedure query
 in metadataIllegalArgumentException - if a query has not been
 defined with the given nameStoredProcedureQuery createStoredProcedureQuery(String procedureName)
procedureName - name of the stored procedure in the
 databaseIllegalArgumentException - if a stored procedure of the
 given name does not exist (or the query execution
 will fail)StoredProcedureQuery createStoredProcedureQuery(String procedureName, Class... resultClasses)
procedureName - name of the stored procedure in the
 databaseresultClasses - classes to which the result sets
 produced by the stored procedure are to
 be mappedIllegalArgumentException - if a stored procedure of the
 given name does not exist (or the query execution
 will fail)StoredProcedureQuery createStoredProcedureQuery(String procedureName, String... resultSetMappings)
procedureName - name of the stored procedure in the
 databaseresultSetMappings - the names of the result set mappings
 to be used in mapping result sets
 returned by the stored procedureIllegalArgumentException - if a stored procedure or
 result set mapping of the given name does not exist
 (or the query execution will fail)void joinTransaction()
TransactionRequiredException - if there is
         no transactionboolean isJoinedToTransaction()
<T> T unwrap(Class<T> cls)
EntityManager
 implementation does not support the specified class, the
 PersistenceException is thrown.cls - the class of the object to be returned.  This is
 normally either the underlying EntityManager implementation
 class or an interface that it implements.PersistenceException - if the provider does not
         support the callObject getDelegate()
EntityManager,
 if available. The result of this method is implementation
 specific. The unwrap method is to be preferred for new
 applications.void close()
EntityManager instance and any
 Query and TypedQuery
 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
 associated with an active transaction, the persistence
 context remains managed until the transaction completes.IllegalStateException - if the entity manager
         is container-managedboolean isOpen()
EntityTransaction getTransaction()
EntityTransaction object.
 The EntityTransaction instance may be used serially to
 begin and commit multiple transactions.IllegalStateException - if invoked on a JTA
         entity managerEntityManagerFactory getEntityManagerFactory()
IllegalStateException - if the entity manager has
         been closedCriteriaBuilder getCriteriaBuilder()
CriteriaBuilder for the creation of
 CriteriaQuery objects.IllegalStateException - if the entity manager has
         been closedMetamodel getMetamodel()
Metamodel interface for access to the
 metamodel of the persistence unit.IllegalStateException - if the entity manager has
         been closed<T> EntityGraph<T> createEntityGraph(Class<T> rootType)
rootType - class of entity graphEntityGraph<?> createEntityGraph(String graphName)
graphName - name of an entity graphEntityGraph<?> getEntityGraph(String graphName)
graphName - name of an existing entity graphIllegalArgumentException - if there is no EntityGraph of the given name<T> List<EntityGraph<? super T>> getEntityGraphs(Class<T> entityClass)
entityClass - entity classIllegalArgumentException - if the class is not an entityCopyright © 2017 JBoss by Red Hat. All rights reserved.