a different object with the same identifier value was already ...一种可能的错误原因

比如如下代码：

 @Test
    public void testSavePerson() {
        try (Session session = sessionFactory.openSession()) {
            Transaction tx = session.beginTransaction();
            Person person = new Person();
            Person person1 = new Person();
            person.setName("222");
            person1.setName("111");
            session.save(person);
            session.save(person1);
            tx.commit();
        }
    }

始终报错，后来才发现是忘记主键自增了！！然后导致两个相同的对象在hibernate中，hibernate不能分辨这连个对象，就报错了！

添加

@GeneratedValue(strategy = GenerationType.AUTO)

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