JpaUtilTests.java 文件源码

@Test
@Transactional
public void testExists() {
    Assert.isTrue(!JpaUtil.exists(User.class), "Not Success.");
    User user = new User();
    user.setId(UUID.randomUUID().toString());
    user.setName("tom");
    User user2 = new User();
    user2.setName("kevin");
    user2.setId(UUID.randomUUID().toString());
    User user3 = new User();
    user3.setName("kevin");
    user3.setId(UUID.randomUUID().toString());

    JpaUtil.persist(user);
    JpaUtil.persist(user2);
    JpaUtil.persist(user3);

    Assert.isTrue(JpaUtil.exists(User.class), "Not Success.");

    EntityManager em = JpaUtil.getEntityManager(User.class);
    CriteriaBuilder cb = em.getCriteriaBuilder();
    CriteriaQuery<User> cq = cb.createQuery(User.class);
    Root<User> root = cq.from(User.class);

    Assert.isTrue(JpaUtil.exists(cq), "Not Success.");

    cq.where(cb.equal(root.get("name"), "tom"));
    Assert.isTrue(JpaUtil.exists(cq), "Not Success.");

    JpaUtil.removeAllInBatch(User.class);
}