持久化一个实体是获取一个临时实体，或者一个在数据库中还没有任何持久化表示的实体，并存储它的状态以便以后可以检索它的操作。
在此示例中，我们创建了一个类型为“DepartmentEntity”的实体并将其持久化到数据库中。

@ContextConfiguration(locations = "classpath:application-context-test.xml")
@RunWith(SpringJUnit4ClassRunner.class)
public class TestPersistEntity {

	@PersistenceContext
    private EntityManager manager;

	@Test
	@Transactional
	@Rollback(true)
	public void testAddDepartment()
	{
		DepartmentEntity department = new DepartmentEntity("Information Technology");
		manager.persist(department);

		List<DepartmentEntity> departments = manager.createQuery("Select a From DepartmentEntity a", 
																	DepartmentEntity.class).getResultList();
		Assert.assertEquals(department.getName(), departments.get(0).getName());
	}
}