/springboot-patterns

name: springboot-patterns
description: Spring Boot 架构模式、REST API 设计、分层服务、数据访问、缓存、异步处理和日志记录。适用于 Java Spring Boot 后端开发。
origin: ECC

Spring Boot 开发模式

适用于可扩展、生产级服务的 Spring Boot 架构和 API 模式。

何时启用

• 使用 Spring MVC 或 WebFlux 构建 REST API
• 组织 控制器 (Controller) → 服务 (Service) → 存储库 (Repository) 层
• 配置 Spring Data JPA、缓存或异步处理
• 添加验证、异常处理或分页
• 为开发/测试/生产环境设置配置文件（Profiles）
• 使用 Spring 事件（Spring Events）或 Kafka 实现事件驱动模式

REST API 结构

@RestController
@RequestMapping("/api/markets")
@Validated
class MarketController {
  private final MarketService marketService;

  MarketController(MarketService marketService) {
    this.marketService = marketService;
  }

  @GetMapping
  ResponseEntity<Page<MarketResponse>> list(
      @RequestParam(defaultValue = "0") int page,
      @RequestParam(defaultValue = "20") int size) {
    Page<Market> markets = marketService.list(PageRequest.of(page, size));
    return ResponseEntity.ok(markets.map(MarketResponse::from));
  }

  @PostMapping
  ResponseEntity<MarketResponse> create(@Valid @RequestBody CreateMarketRequest request) {
    Market market = marketService.create(request);
    return ResponseEntity.status(HttpStatus.CREATED).body(MarketResponse.from(market));
  }
}

存储库模式（Spring Data JPA）

public interface MarketRepository extends JpaRepository<MarketEntity, Long> {
  @Query("select m from MarketEntity m where m.status = :status order by m.volume desc")
  List<MarketEntity> findActive(@Param("status") MarketStatus status, Pageable pageable);
}

带事务的服务层

@Service
public class MarketService {
  private final MarketRepository repo;

  public MarketService(MarketRepository repo) {
    this.repo = repo;
  }

  @Transactional
  public Market create(CreateMarketRequest request) {
    MarketEntity entity = MarketEntity.from(request);
    MarketEntity saved = repo.save(entity);
    return Market.from(saved);
  }
}

DTO 与验证

public record CreateMarketRequest(
    @NotBlank @Size(max = 200) String name,
    @NotBlank @Size(max = 2000) String description,
    @NotNull @FutureOrPresent Instant endDate,
    @NotEmpty List<@NotBlank String> categories) {}

public record MarketResponse(Long id, String name, MarketStatus status) {
  static MarketResponse from(Market market) {
    return new MarketResponse(market.id(), market.name(), market.status());
  }
}

异常处理

@ControllerAdvice
class GlobalExceptionHandler {
  @ExceptionHandler(MethodArgumentNotValidException.class)
  ResponseEntity<ApiError> handleValidation(MethodArgumentNotValidException ex) {
    String message = ex.getBindingResult().getFieldErrors().stream()
        .map(e -> e.getField() + ": " + e.getDefaultMessage())
        .collect(Collectors.joining(", "));
    return ResponseEntity.badRequest().body(ApiError.validation(message));
  }

  @ExceptionHandler(AccessDeniedException.class)
  ResponseEntity<ApiError> handleAccessDenied() {
    return ResponseEntity.status(HttpStatus.FORBIDDEN).body(ApiError.of("Forbidden"));
  }

  @ExceptionHandler(Exception.class)
  ResponseEntity<ApiError> handleGeneric(Exception ex) {
    // 记录带有堆栈跟踪的非预期错误
    return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
        .body(ApiError.of("Internal server error"));
  }
}

缓存

需要在配置类上添加 `@EnableCaching`。

@Service
public class MarketCacheService {
  private final MarketRepository repo;

  public MarketCacheService(MarketRepository repo) {
    this.repo = repo;
  }

  @Cacheable(value = "market", key = "#id")
  public Market getById(Long id) {
    return repo.findById(id)
        .map(Market::from)
        .orElseThrow(() -> new EntityNotFoundException("Market not found"));
  }

  @CacheEvict(value = "market", key = "#id")
  public void evict(Long id) {}
}

异步处理

需要在配置类上添加 `@EnableAsync`。

@Service
public class NotificationService {
  @Async
  public CompletableFuture<Void> sendAsync(Notification notification) {
    // 发送电子邮件/短信
    return CompletableFuture.completedFuture(null);
  }
}

日志记录 (SLF4J)

@Service
public class ReportService {
  private static final Logger log = LoggerFactory.getLogger(ReportService.class);

  public Report generate(Long marketId) {
    log.info("generate_report marketId={}", marketId);
    try {
      // 逻辑
    } catch (Exception ex) {
      log.error("generate_report_failed marketId={}", marketId, ex);
      throw ex;
    }
    return new Report();
  }
}

中间件 / 过滤器

@Component
public class RequestLoggingFilter extends OncePerRequestFilter {
  private static final Logger log = LoggerFactory.getLogger(RequestLoggingFilter.class);

  @Override
  protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
      FilterChain filterChain) throws ServletException, IOException {
    long start = System.currentTimeMillis();
    try {
      filterChain.doFilter(request, response);
    } finally {
      long duration = System.currentTimeMillis() - start;
      log.info("req method={} uri={} status={} durationMs={}",
          request.getMethod(), request.getRequestURI(), response.getStatus(), duration);
    }
  }
}

分页和排序

PageRequest page = PageRequest.of(pageNumber, pageSize, Sort.by("createdAt").descending());
Page<Market> results = marketService.list(page);

具有容错能力的外部调用

public <T> T withRetry(Supplier<T> supplier, int maxRetries) {
  int attempts = 0;
  while (true) {
    try {
      return supplier.get();
    } catch (Exception ex) {
      attempts++;
      if (attempts >= maxRetries) {
        throw ex;
      }
      try {
        Thread.sleep((long) Math.pow(2, attempts) * 100L);
      } catch (InterruptedException ie) {
        Thread.currentThread().interrupt();
        throw ex;
      }
    }
  }
}

速率限制（过滤器 + Bucket4j）

**安全提示**：默认情况下 `X-Forwarded-For` 请求头是不可信的，因为客户端可以伪造它。 仅在以下情况使用转发头： 1. 应用位于受信任的反向代理（nginx、AWS ALB 等）之后 2. 已将 `ForwardedHeaderFilter` 注册为 Bean 3. 已在应用属性中配置了 `server.forward-heade