lock(entity, lockMode, properties) - JPA EntityManager's method
Method javax.persistence.EntityManager
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
PessimisticLockExceptionwill be thrown if the database locking failure causes transaction-level rollback - the
LockTimeoutExceptionwill 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 -
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:
- JPA 2.0
