getReference(entityClass, primaryKey) - JPA EntityManager's method
Method javax.persistence.EntityManager
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
- Since:
- JPA 1.0
