spring - Jpa测试和Spring自动回滚

Question

我指的是 Spring Roo In Action(Manning 的书)。书中某处说“Roo 将测试类标记为@Transactional，以便单元测试自动回滚任何更改。

这里是说明方法:

@Test
@Transactional
  public void addAndFetchCourseViaRepo() {
    Course c = new Course();
    c.setCourseType(CourseTypeEnum.CONTINUING_EDUCATION);
    c.setName("Stand-up Comedy");
    c.setDescription(
      "You'll laugh, you'll cry, it will become a part of you.");
    c.setMaxiumumCapacity(10);

    c.persist();
    c.flush();
    c.clear();  
    Assert.assertNotNull(c.getId());

    Course c2 = Course.findCourse(c.getId());
    Assert.assertNotNull(c2);
    Assert.assertEquals(c.getName(), c2.getName());
    Assert.assertEquals(c2.getDescription(), c.getDescription());
    Assert.assertEquals(
      c.getMaxiumumCapacity(), c2.getMaxiumumCapacity());
    Assert.assertEquals(c.getCourseType(), c2.getCourseType());
  }

但是，我不明白为什么如果没有发生 RuntimeException，此方法中的更改会自动回滚...

Answer 1

引自 documentation :

By default, the framework will create and roll back a transaction for each test. You simply write code that can assume the existence of a transaction. [...] In addition, if test methods delete the contents of selected tables while running within a transaction, the transaction will roll back by default, and the database will return to its state prior to execution of the test. Transactional support is provided to your test class via a PlatformTransactionManager bean defined in the test's application context.

因此，换句话说，运行测试的 SpringJUnit4ClassRunner 总是在测试执行后进行事务回滚。