Cascade：HIbernate中级联的使用

@ManyToOne(cascade={CascadeType.ALL})
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this.group = group;
}

@Test
public void testSaveUser(){
User u = new User();
Group g = new Group();
u.setName("u1");
u.setGroup(g);
g.setName("g1");

Session session = sessionFactory.getCurrentSession();
session.beginTransaction();
//	        session.save(g);
session.save(u);
session.getTransaction().commit();
}