Why in JPA EntityManager queries throw NoResultException but find does not?

Question

Can somebody tell me the intrinsic reasons why in the JPA 1.0 EntityManager when retrieving an Object via find, you have to deal with null if not found, but when using the Q

Answer 1

When you do a find, jpa will use the primary key to locate the entity object, often using second level cache and it is typically much faster than createQuery and getSingleResult.

You either get null or the Object back from find. When you do a createQuery and instance of Query object is created. If you do a getResultList it will not throw a NoResultException, only if you do a getSingleResult will it throw that exception. If you do a getResultList and none is found, then null will be returned.