Spring集成测试中事务隔离与MockMvc的陷阱：旧数据为何依然可见？

@Test
@Transactional // 这里的事务导致了问题
void test() {
    User user = userRepository.findUserByUniqueName("oldUniqueName").orElse(null);
    assertThat(user).isNotNull();

    user.setUniqueName("newUniqueName");
    userRepository.saveAndFlush(user); // 修改在此事务中，未提交

    // headers中添加oldUniqueName
    HttpHeaders headers = new HttpHeaders();
    headers.add("Unique-Name", "oldUniqueName"); 

    mockMvc
        .perform(get("/api/user").headers(headers)) // mockMvc请求
        .andExpect(status().isUnauthorized()); // 预期未授权，因为找不到oldUniqueName的用户
}

// 安全过滤器中的查询逻辑
@Override
@Transactional // 过滤器可能也有自己的事务
protected void doFilterInternal(
      HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
      throws ServletException, IOException {

    String oldUniqueName = extractUniqueNameFromRequest(request);
    try {
        // 这里的查询是在mockMvc请求的上下文中执行的，
        // 它看不到上面测试方法中未提交的修改
        User user = userRepository.findUserByUniqueName(oldUniqueName).orElseThrow(new Exception());
        // ... 更新安全上下文
    }
    catch(Exception e) {
        // ... 处理异常
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.support.TransactionTemplate;
import org.springframework.http.HttpHeaders;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.assertj.core.api.Assertions.assertThat;

@SpringBootTest
@AutoConfigureMockMvc
class UserIntegrationTest {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private MockMvc mockMvc;

    @Autowired
    private PlatformTransactionManager transactionManager; // 注入事务管理器

    @Test
    void testUserUpdateVisibility() throws Exception {
        // 使用TransactionTemplate确保此块内的操作被提交
        new TransactionTemplate(transactionManager).executeWithoutResult(status -> {
            User user = new User("oldUniqueName"); // 假设User有一个构造函数
            userRepository.save(user); // 保存初始用户

            User foundUser = userRepository.findUserByUniqueName("oldUniqueName").orElse(null);
            assertThat(foundUser).isNotNull();

            foundUser.setUniqueName("newUniqueName");
            userRepository.saveAndFlush(foundUser); // 更新用户并刷新
        });
        // 至此，对数据库的修改（oldUniqueName -> newUniqueName）已提交

        // 模拟mockMvc请求，此时数据库中已无"oldUniqueName"的用户
        HttpHeaders headers = new HttpHeaders();
        headers.add("Unique-Name", "oldUniqueName"); 

        mockMvc
            .perform(get("/api/user").headers(headers))
            .andExpect(status().isUnauthorized()); // 预期未授权，因为找不到oldUniqueName的用户

        // 可选：在测试结束时清理数据，以保持数据库状态清洁
        new TransactionTemplate(transactionManager).executeWithoutResult(status -> {
            userRepository.findUserByUniqueName("newUniqueName").ifPresent(userRepository::delete);
        });
    }
}