This week's book giveaway is in the Design forum.
We're giving away four copies of Design for the Mind and have Victor S. Yocco on-line!
See this thread for details.
Win a copy of Design for the Mind this week in the Design forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

A Mock Aboute EntityManager

 
Fu Dong Jia
Ranch Hand
Posts: 131
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Given:
11. @PersistenceContext EntityManager em;
12. public boolean test(Order o) {
13. boolean b = false;
14. o = em.merge(o);
15 em.remove(o);
16. o = em.merge(o);
17. b = em.contains(o);
18. return b;
19. }
Pass4Side SUN 310-091
Pass4Side Help you pass any IT Exams! Page 5 of 9
Which statement is correct?
A. The method will return TRUE.
B. The method will return FALSE.
C. The method will throw an exception.
D. The Order instance will be removed from the database.
Answer: C

Why the answer is c?
 
Chaminda Amarasinghe
Ranch Hand
Posts: 410
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
javadocs of EM for merge


/**
* Merge the state of the given entity into the
* current persistence context.
* @param entity
* @return the instance that the state was merged to
* @throws IllegalArgumentException if instance is not an
* entity or is a removed entity
* @throws TransactionRequiredException if invoked on a
* container-managed entity manager of type
* PersistenceContextType.TRANSACTION and there is
* no transaction.
*/
public <T> T merge(T entity);
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic