@Test
public void testFetchJoin2() {
log.info("** testFetchJoin2() ***");
EntityManager em2 = createEm();
CriteriaBuilder cb = em2.getCriteriaBuilder();
CriteriaQuery<Store> qdef = cb.createQuery(Store.class);
// select s from Store s JOIN FETCH s.sales
// where s.name='Big Al''s'
Root<Store> s = qdef.from(Store.class);
s.fetch("sales");
qdef.select(s).where(cb.equal(s.get("name"), "Big Al's"));
Store store = em2.createQuery(qdef).getSingleResult();
log.info("em.contains(" + em2.contains(store) + ")");
em2.close();
store.getSales().get(0).getAmount();
}
/**
* This test demonstrates the function of a JOIN FETCH to perform the EAGER retrieval of entities
* as a side-effect of the query
*/
@Test
public void testFetchJoin1() {
log.info("** testFetchJoin1() ***");
EntityManager em2 = createEm();
CriteriaBuilder cb = em2.getCriteriaBuilder();
CriteriaQuery<Store> qdef = cb.createQuery(Store.class);
// select s from Store s JOIN s.sales
// where s.name='Big Al''s'
Root<Store> s = qdef.from(Store.class);
s.join("sales");
qdef.select(s).where(cb.equal(s.get("name"), "Big Al's"));
Store store = em2.createQuery(qdef).getSingleResult();
log.info("em.contains(" + em2.contains(store) + ")");
em2.close();
try {
store.getSales().get(0).getAmount();
fail("did not trigger lazy initialization exception");
} catch (LazyInitializationException expected) {
log.info("caught expected exception:" + expected);
}
}