Question

测试方法remove正在尝试删除标识为147的某些用户，但此ID不存在。如果我启用Rollback(false)我会得到一个异常（预期的行为）但没有它，测试通过没有问题。所以我有两个问题：

为什么测试仅在禁用回滚时失败？
是否有可能获得启用回滚的异常？

UserDao继承自通用DAO类，它在类级别具有@Transactional（默认选项）和@Repository（带有bean名称）注释。

Here是我在禁用回滚时获得的异常。

我正在使用Spring Framework 4.3.9，Hibernate 5.2.10和JUnit 4.12

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@Transactional
@ContextConfiguration({
        "classpath:myapp-config-test.xml",
        "classpath:hib-test.xml"})
public class UserControllerTest {

    private MockMvc mockMvc;
    private MvcResult mvcResult;
    private final String basePath = "/users/";

    @Autowired
    private UserDao userDao;

    @Before
    public void setUp() throws Exception {
        mockMvc = MockMvcBuilders.standaloneSetup(new UserController(userDao)).build();
    }

    @Test
    //@Rollback(false)
    public void remove() throws Exception {
        mockMvc.perform(delete(basePath + "147")).andExpect(status().isOk());
    }
}

Answer 1

从下到上阅读堆栈跟踪：

Caused by: org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:67)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:54)
    at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:46)
    at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:3315)
    at org.hibernate.persister.entity.AbstractEntityPersister.delete(AbstractEntityPersister.java:3552)
    at org.hibernate.action.internal.EntityDeleteAction.execute(EntityDeleteAction.java:99)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:589)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:463)
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:337)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1435)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:491)
    at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3201)
    at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2411)
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:467)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:146)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:220)
    at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)
    at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:582)
    ... 24 more

您可以看到事务管理器提交事务时发生异常：

at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:582)

提交事务会导致Hibernate会话刷新已经发生的更改并保存在内存中：

at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3201)

实际上，flush会导致删除实际上在数据库上执行：

at org.hibernate.action.internal.EntityDeleteAction.execute(EntityDeleteAction.java:99)

由于删除不删除任何内容，因此抛出异常：

org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

因此，为了实际执行删除并抛出预期的异常，您需要刷新。

但是你不应该在MVC控制器的单元测试中测试DAO的行为（甚至更少，Hibernate的行为，已经由Hibernate本身测试过）。相反，您应该在对控制器进行单元测试时模拟控制器（即DAO）的依赖关系。并对DAO进行了另一次测试。

事务测试方法在使用回滚时不抛出异常

1 个答案: