我使用的是Spring Data JPA和Spring Boot。

main
    +-- java
        +-- com/lapots/game/monolith
            +-- repository/relational
                +--RelationalPlayerRepository.java
            +-- web
                +--GrandJourneyMonolithApplication.java
                +-- config
                    +-- RelationalDBConfiguration.java
test
    +-- java
        +-- com/lapots/game/monolith
            +-- repository/relational
                +-- RelationalPlayerRepositoryTests.java
            +-- web
                +-- GrandJourneyMonolithApplicationTests.java

对象的存储库如下所示

public interface RelationalPlayerRepository extends JpaRepository<Player, Long> {
}

此外，我还为存储库提供了一个配置

@Configuration
@EnableJpaRepositories(basePackages = "com.lapots.game.monolith.repository.relational")
@EntityScan("com.lapots.game.monolith.domain")
public class RelationalDBConfiguration {
}

我的主应用程序如下所示

@SpringBootApplication
@ComponentScan("com.lapots.game.monolith")
public class GrandJourneyMonolithApplication {

    @Autowired
    private RelationalPlayerRepository relationalPlayerRepository;

    public static void main(String[] args) {
        SpringApplication.run(GrandJourneyMonolithApplication.class, args);
    }

    @Bean
    public CommandLineRunner initPlayers() {
        return (args) -> {
            Player p = new Player();
            p.setLevel(10);
            p.setName("Master1909");
            p.setClazz("warrior");

            relationalPlayerRepository.save(p);
        };
    }
}

应用程序的测试如下所示

@RunWith(SpringRunner.class)
@SpringBootTest
public class GrandJourneyMonolithApplicationTests {

    @Test
    public void contextLoads() {
    }

}

存储库的测试如下所示

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

    @Autowired
    private TestEntityManager entityManager;

    @Autowired
    private RelationalPlayerRepository repository;

    @Test
    public void testBasic() {
        Player expected = createPlayer("Master12", "warrior", 10);
        this.entityManager.persist(expected);
        List<Player> players = repository.findAll();
        assertThat(repository.findAll()).isNotEmpty();
        assertEquals(expected, players.get(0));
    }

    private Player createPlayer(String name, String clazz, int level) {
        Player p = new Player();
        p.setId(1L);
        p.setName(name);
        p.setClazz(clazz);
        p.setLevel(level);
        return p;
    }
}

但是当我尝试运行测试时，我得到了错误

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.041 sec <<< FAILURE! - in com.lapots.game.monolith.repository.relational.RelationalPlayerRepositoryTests
initializationError(com.lapots.game.monolith.repository.relational.RelationalPlayerRepositoryTests)  Time elapsed: 0.006 sec  <<< ERROR!
java.lang.IllegalStateException: Unable to find a @SpringBootConfiguration, you need to use @ContextConfiguration or @SpringBootTest(classes=...) with your test
at org.springframework.util.Assert.state(Assert.java:70)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.getOrFindConfigurationClasses(SpringBootTestContextBootstrapper.java:202)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.processMergedContextConfiguration(SpringBootTestContextBootstrapper.java:137)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:409)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildDefaultMergedContextConfiguration(AbstractTestContextBootstrapper.java:323)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildMergedContextConfiguration(AbstractTestContextBootstrapper.java:277)
at org.springframework.test.context.support.AbstractTestContextBootstrapper.buildTestContext(AbstractTestContextBootstrapper.java:112)
at org.springframework.boot.test.context.SpringBootTestContextBootstrapper.buildTestContext(SpringBootTestContextBootstrapper.java:82)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:120)
at org.springframework.test.context.TestContextManager.<init>(TestContextManager.java:105)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTestContextManager(SpringJUnit4ClassRunner.java:152)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<init>(SpringJUnit4ClassRunner.java:143)
at org.springframework.test.context.junit4.SpringRunner.<init>(SpringRunner.java:49)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:104)
at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:33)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:283)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:173)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:128)
at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:203)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:155)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)

问题是什么？域Player看起来像这样

@Data
@Entity
@Table(schema = "app", name = "players")
public class Player {
    @Id
    @GeneratedValue
    private Long id;

    @Transient
    Set<Player> comrades;

    @Column(unique = true)
    private String name;

    private int level;

    @Column(name = "class")
    private String clazz;
}