T find(
  Class<T> entityClass,
  Object primaryKey,
  LockModeType lockMode
)

Find by primary key and obtain the given lock type for the resulting entity. 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 EntityManager.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 is thrown.

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

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

Parameters:

entityClass - entity class

lockMode - lock mode

primaryKey - primary key

Returns:

the found entity instance or null if the entity does not exist.

Throws:

PessimisticLockException - if pessimistic locking fails and the transaction is rolled back.

LockTimeoutException - if pessimistic locking fails and only the statement is rolled back.

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.

PersistenceException - if an unsupported lock call is made.

OptimisticLockException - if the optimistic version check fails.

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.

Since:

Jakarta Persistence (JPA) 2.0