Question

我有一个具有乐观锁机制的实体Person。一个人有几个手指。如果任何一个手指改变，我希望Person的乐观锁定计数器计数。

@Test
public void testVersionUpOnChildChange() throws Exception {
    // persist entities => version is initially created
    doInTransaction(new HibernateMethod() {
        @Override
        public void run(Session session) {
            michael = new Person("Michael");
            michael.setId(1);
            michael.addFinger(new Finger("Thumb", michael));
            michael.addFinger(new Finger("Ringfinger", michael));
            michael.addFinger(new Finger("Index", michael));
            session.persist(michael);
        }
    });
    Assert.assertEquals(0, michael.getVersion().intValue());

    // just read michael from database => michaels version counter should stay as it is
    doInTransaction(new HibernateMethod() {
        @Override
        public void run(Session session) {
            michael = (Person) session.get(Person.class, 1);
            session.update(michael);
        }
    });
    Assert.assertEquals(0, michael.getVersion().intValue());

    // do changes to michael directly => version counter goes up
    doInTransaction(new HibernateMethod() {
        @Override
        public void run(Session session) {
            michael = (Person) session.get(Person.class, 1);
            michael.setName("Der Bulla");
            session.update(michael);
        }
    });
    Assert.assertEquals(1, michael.getVersion().intValue());


    // add a new finger to michael => version counter goes up
    doInTransaction(new HibernateMethod() {
        @Override
        public void run(Session session) {
            michael = (Person) session.get(Person.class, 1);
            Finger finger = new Finger("Small finger", michael);
            michael.addFinger(finger);
            session.update(michael);
        }
    });
    Assert.assertEquals(2, michael.getVersion().intValue());

    // here's the tricky part: change a finger of michael without any changes to michael itself => version counter goes up
    doInTransaction(new HibernateMethod() {
        @Override
        public void run(Session session) {
            michael = (Person) session.get(Person.class, 1);
            Assert.assertEquals(michael.getFingers().size(), 4);
            Finger anyFinger = michael.getFingers().iterator().next();
            anyFinger.setName("Middlefinger");
            session.update(anyFinger);
        }
    });
    Assert.assertEquals(3, michael.getVersion().intValue());
}

Assert.assertEquals(3, michael.getVersion().intValue());失败，因为如果依赖手指发生变化，Hibernate并不关心更新某个人的版本计数器。我能说服Hibernate吗？

Answer 1

如果我理解你的问题，那么你正在寻找的解决方案可能是

  @OptimisticLock(excluded=true)

只需将此注释放入手指集合列表即可。希望我能正确理解你的问题。

如果依赖实体变脏，则使hibernate实体变脏

1 个答案: