Spring数据JPA存储库上invoke count()方法时的JPA缓存行为

为了检查表中的行数,我使用了side JDBCTemplate。

org.springframework.data.repository.CrudRepository#save(S) 不会生效。SQL insert in未执行,表中的行数未增加。

org.springframework.data.repository.CrudRepository#count 之后 save(S)

我猜这是JPA缓存的行为,但它是如何工作的呢?

弹簧靴代码:

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

    @Autowired
    private ErrorMessageEntityRepository errorMessageEntityRepository;
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Test
    @Transactional
    public void save() {
        ErrorMessageEntity errorMessageEntity = aDefaultErrorMessageEntity().withUuid(null).build();
        assertTrue(TestTransaction.isActive());
        int sizeBefore= JdbcTestUtils.countRowsInTable(jdbcTemplate, "error_message");
        ErrorMessageEntity saved = errorMessageEntityRepository.save(errorMessageEntity);
        errorMessageEntityRepository.count(); // [!!!!] if comment this line test will fail
        int sizeAfter= JdbcTestUtils.countRowsInTable(jdbcTemplate, "error_message");
        Assert.assertEquals(sizeBefore+1, sizeAfter);
    }

实体:

@Entity(name = "error_message")
public class ErrorMessageEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private UUID uuid;
    @NotNull
    private String details;

存储库:

public interface ErrorMessageEntityRepository extends CrudRepository<ErrorMessageEntity, UUID>