save方法 - 在发生异常后不刷新会话

Question

public class SoftwareTest extends UnitTest {

    @Before
    public void setup() {
        Fixtures.deleteAll(); // will fail if comment that. why?????
    }

    @Test
    public void createSoftwareWithNullAuthor()  {

       // when author is null

       Author nullAuthor = null;

       Software software = new Software("software1", "description1", nullAuthor);
       try {
         software.save();
         fail("author should not be null");
       } catch (PersistenceException ex) {
       }

    }


    @Test
    public void createSoftwareWithOkAuthor()  {
       // when author is ok
       Author okAuthor = new Author("author1", "email1").save(); // ERROR HERE!

       Software software2 = new Software("software2", "description2", okAuthor);
       Software savedSoftware = software2.save();
       assertNotNull(savedSoftware);
       assertEquals(savedSoftware, software2); 

       assertNotNull(savedSoftware.author);
       assertEquals(okAuthor, savedSoftware.author);
    }
}

当取消注释该行时,Fixtures.deleteAll()我们将在第二种方法中获得异常 - createSoftwareWithOkAuthor() 当save()作者.为什么会这样？

org.hibernate.AssertionFailure: null id in models.Software entry (don't flush the Session after an exception occurs)
  at org.hibernate.event.def.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:82)
  at org.hibernate.event.def.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:190)
  at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:147)
  at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:240)
  at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)
  at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
  at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)

Answer 1

从错误:

org.hibernate.AssertionFailure:null id在models.Software入口中(不要Session在发生异常后刷新)

我们可以看到之前发生过会话异常.其中,该点org.hibernate.AssertionFailure被抛出不到哪错误内容时发生了点.

那就是:有些东西正在压制原来的例外.

因此,寻找其他可能的错误点.A save()或者saveOrUpdate()可能尝试持久化具有null字段的实体,其中列在表中NOT NULL.

在我的情况下,真正的例外发生在一个try/catch {}阻止异常的区块内catch(没有重新抛出或警告我).

Answer 2

问题似乎是Hibernate引发了一个异常(因此当前事务失效)但是你试图在该会话中继续进行更多的操作.

执行此操作的正确方法是将您正在使用的测试拆分为2,一部分用于测试空作者,另一部分用有效作者进行测试.

在生产代码(比如说控制器)上,您需要重新启动操作(关闭事务,重新启动进程)才能继续.但是考虑到play管理事务的方式,正常的行为是在错误之后你将返回错误消息给用户.