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 if the second argument is not a valid type for that entity's primary key or is null.

Since:

Jakarta Persistence (JPA) 1.0