SpringBoot请求体缺失异常原因分析与处理方案

// Axios示例
axios.put('/api/user/edit', {
  oldPassword: 'currentPassword123',
  newPassword: 'newPassword456'
}, {
  headers: {
    'Content-Type': 'application/json'
  }
})
// Fetch API示例
fetch('/api/user/edit', {
  method: 'PUT',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    oldPassword: 'currentPassword123',
    newPassword: 'newPassword456'
  })
})

@RestController
@RequestMapping("/api/user")
public class UserController {
    @PutMapping("/edit")
    public ResponseEntity<?> edit(@RequestBody(required = false) UserUpdatePwdDTO dto) {
        if (dto == null) {
            return ResponseEntity.badRequest().body("请求体不能为空");
        }
        // 业务逻辑处理
        userService.updatePassword(dto);
        return ResponseEntity.ok("密码修改成功");
    }
}

@ControllerAdvice
public class GlobalExceptionHandler {
    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);
    @ExceptionHandler(HttpMessageNotReadableException.class)
    public ResponseEntity<ErrorResponse> handleHttpMessageNotReadable(
            HttpMessageNotReadableException ex) {
        logger.error("请求体解析异常: {}", ex.getMessage());
        ErrorResponse errorResponse = new ErrorResponse();
        errorResponse.setCode("BAD_REQUEST");
        errorResponse.setMessage("请求参数格式错误或请求体缺失");
        errorResponse.setTimestamp(LocalDateTime.now());
        return ResponseEntity.badRequest().body(errorResponse);
    }
    // 错误响应DTO
    @Data
    public static class ErrorResponse {
        private String code;
        private String message;
        private LocalDateTime timestamp;
    }
}

@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface OptionalRequestBody {
    // 自定义注解用于可选请求体
}
// 对应的解析器
public class OptionalRequestBodyResolver implements HandlerMethodArgumentResolver {
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.hasParameterAnnotation(OptionalRequestBody.class);
    }
    @Override
    public Object resolveArgument(MethodParameter parameter, 
                                 ModelAndViewContainer mavContainer,
                                 NativeWebRequest webRequest, 
                                 WebDataBinderFactory binderFactory) throws Exception {
        // 自定义解析逻辑
        return null; // 根据实际情况实现
    }
}

@Data
public class UserUpdatePwdDTO {
    @NotBlank(message = "旧密码不能为空")
    private String oldPassword;
    @NotBlank(message = "新密码不能为空")
    @Size(min = 6, max = 20, message = "密码长度必须在6-20位之间")
    private String newPassword;
    // 默认构造函数
    public UserUpdatePwdDTO() {}
    // 全参构造函数
    public UserUpdatePwdDTO(String oldPassword, String newPassword) {
        this.oldPassword = oldPassword;
        this.newPassword = newPassword;
    }
}

@SpringBootTest
@AutoConfigureTestDatabase
class UserControllerTest {
    @Autowired
    private TestRestTemplate restTemplate;
    @Test
    void shouldReturnBadRequestWhenBodyMissing() {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        HttpEntity<String> request = new HttpEntity<>(null, headers);
        ResponseEntity<String> response = restTemplate
            .exchange("/api/user/edit", HttpMethod.PUT, request, String.class);
        assertEquals(HttpStatus.BAD_REQUEST, response.getStatusCode());
    }
}

// 请求拦截器
axios.interceptors.request.use(config => {
  if (['POST', 'PUT', 'PATCH'].includes(config.method.toUpperCase())) {
    if (!config.headers['Content-Type']) {
      config.headers['Content-Type'] = 'application/json';
    }
  }
  return config;
});
// 响应拦截器 - 统一处理400错误
axios.interceptors.response.use(
  response => response,
  error => {
    if (error.response?.status === 400) {
      // 统一处理请求体缺失等错误
      showErrorMessage('请求参数错误，请检查后重试');
    }
    return Promise.reject(error);
  }
);