@DataJpaTest不能与@GenericGenerator一起使用

Question

我试图用DataJpaTest注释测试我的存储库，但出现了一些奇怪的情况。

当我使用经典的@GeneratedValue时，一切正常，我的测试成功了。但是当我使用下面的生成器时，我的测试失败了。

测试应该成功，但其他测试没有成功，因为没有抛出关于约束有效性的异常。

@GeneratedValue(generator = "UUID")
@GenericGenerator(name = "UUID", strategy = "com.example.demojpa.CustomIdentifierGenerator") 

例如，这里有一个失败的断言：

Java语言AssertionError：预期测试将抛出org的实例。springframework。道。DataIntegrityViolationException数据完整性异常

at org.junit.Assert.fail(Assert.java:88)
at org.junit.rules.ExpectedException.failDueToMissingException(ExpectedException.java:263)
at org.junit.rules.ExpectedException.access$200(ExpectedException.java:106)
at org.junit.rules.ExpectedException$ExpectedExceptionStatement.evaluate(ExpectedException.java:245)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

@NoArgsConstructor
@Data
@Entity()
@Table(name = "mw_ecom_country", uniqueConstraints = {@UniqueConstraint(name = "abbreviation", columnNames = "abbreviation")})
public class Country {

    @Id
    @GeneratedValue
    //@GeneratedValue(generator = "UUID")
    //@GenericGenerator(name = "UUID", strategy = "com.example.demojpa.CustomIdentifierGenerator")
    protected Long id;

    @NotNull
    @NotEmpty
    private String abbreviation;

    @NotNull
    private String name;

    public Country(Long id, String abbreviation, String name) {
        this.id = id;
        this.abbreviation = abbreviation;
        this.name = name;
    }
}

@DataJpaTest
@RunWith(SpringRunner.class)
public class CountryRepoTest {

    @Autowired
    private CountryRepository countryRepository;

    @Rule
    public ExpectedException exception = ExpectedException.none();

    @Test
    public void createCountry_should_succeed() {
        Country country = countryRepository.save(new Country(null, "FR", "France"));
        assertThat(country.getId(), notNullValue());
    }

    @Test
    public void createCountry_should_failed_duplicate_abbreviation() {
        exception.expect(DataIntegrityViolationException.class);
        countryRepository.save(new Country(null, "FR", "France"));
        countryRepository.save(new Country(null, "FR", "France"));
    }

    @Test
    public void createCountry_should_failed_null_abbreviation() {
        exception.expect(ConstraintViolationException.class);
        countryRepository.save(new Country(null, null, "France"));
    }

    @Test
    public void createCountry_should_failed_empty_abbreviation() {
        exception.expect(ConstraintViolationException.class);
        countryRepository.save(new Country(null, "", "France"));

    }
}

public class CustomIdentifierGenerator implements IdentifierGenerator {

    @Override
    public Serializable generate(SessionImplementor session, Object object) throws HibernateException {
        return new Random().nextLong();
    }
}

也许是虫子？https://github.com/spring-projects/spring-boot/issues/14711

Answer 1

这很可能是因为您的实体从未被写入数据库。

JPA充当一个写后缓存。如果它不必向数据库写入更改，它会尽可能长时间地延迟它。当数据库生成ID时，它必须实际执行插入以获取ID。这会触发异常。当在JVM中生成ID时，插入只会在刷新期间发生。

但是在您的测试中，事务从未提交，而是回滚，因此您永远不会看到异常。

使用JpaRepository。保存并刷新，或将EntityManager注入测试中，并在测试结束时对其调用刷新。

另请参见：Spring数据JPA存储库上调用count（）方法时的JPA缓存行为