本课程采用k8s+springboot, k8s自带服务发现LB等一系列微服务治理能力, 无需springcloud

工程结构

image.png

接口参数校验

采用springValidation

  1. // 采用@Valid校验请求体
  2. @PostMapping(path = "/get_or_create")
  3. public GenericAccountResponse getOrCreate(@RequestBody @Valid GetOrCreateRequest request) {
  4. ...}
  6. // 直接校验路径参数
  7. public GenericAccountResponse getAccount(@RequestParam @NotBlank String userId) {
  8. ...}
  10. // 采用自定义注解
  11.  public GenericAccountResponse getAccountByPhonenumber(@RequestParam @PhoneNumber String phoneNumber){
  12. ...}

自定义注解进行参数校验

  1. @Documented
  2. @Constraint(validatedBy = PhoneNumberValidator.class)
  3. @Target({ElementType.FIELD, ElementType.PARAMETER})
  4. @Retention(RetentionPolicy.RUNTIME)
  5. public @interface PhoneNumber {
  6.     String message() default "Invalid phone number";
  7.     Class[] groups() default {};
  8.     Class[] payload() default {};
  9. }
  1. public class PhoneNumberValidator implements ConstraintValidator<PhoneNumber, String> {
  3.     @Override
  4.     public boolean isValid(String phoneField, ConstraintValidatorContext context) {
  5.         if (phoneField == null) return true; // can be null
  6.         return phoneField != null && phoneField.matches("[0-9]+")
  7.                 && (phoneField.length() > 8) && (phoneField.length() < 14);
  8.     }
  9. }

统一异常处理

restful

使用RestControllerAdvice来进行统一异常处理
image.png

自定义业务异常

  1. public class ServiceException extends RuntimeException {
  2.     private static final long serialVersionUID = 2359767895161832954L;
  4.     @Getter
  5.     private final ResultCode resultCode;
  7.     public ServiceException(String message) {
  8.         super(message);
  9.         this.resultCode = ResultCode.FAILURE;
  10.     }
  12.     public ServiceException(ResultCode resultCode) {
  13.         super(resultCode.getMsg());
  14.         this.resultCode = resultCode;
  15.     }
  17.     public ServiceException(ResultCode resultCode, String msg) {
  18.         super(msg);
  19.         this.resultCode = resultCode;
  20.     }
  22.     public ServiceException(ResultCode resultCode, Throwable cause) {
  23.         super(cause);
  24.         this.resultCode = resultCode;
  25.     }
  27.     public ServiceException(String msg, Throwable cause) {
  28.         super(msg, cause);
  29.         this.resultCode = ResultCode.FAILURE;
  30.     }
  32.     /**
  33.      * for better performance
  34.      *
  35.      * @return Throwable
  36.      */
  37.     @Override
  38.     public Throwable fillInStackTrace() {
  39.         return this;
  40.     }
  42.     public Throwable doFillInStackTrace() {
  43.         return super.fillInStackTrace();
  44.     }
  45. }

GlobalExceptionTranslator

  1. @RestControllerAdvice
  2. public class GlobalExceptionTranslator {
  4.     static final ILogger logger = SLoggerFactory.getLogger(GlobalExceptionTranslator.class);
  6.     @ExceptionHandler(MissingServletRequestParameterException.class)
  7.     public BaseResponse handleError(MissingServletRequestParameterException e) {
  8.         logger.warn("Missing Request Parameter", e);
  9.         String message = String.format("Missing Request Parameter: %s", e.getParameterName());
  10.         return BaseResponse
  11.                 .builder()
  12.                 .code(ResultCode.PARAM_MISS)
  13.                 .message(message)
  14.                 .build();
  15.     }
  17.     @ExceptionHandler(MethodArgumentTypeMismatchException.class)
  18.     public BaseResponse handleError(MethodArgumentTypeMismatchException e) {
  19.         logger.warn("Method Argument Type Mismatch", e);
  20.         String message = String.format("Method Argument Type Mismatch: %s", e.getName());
  21.         return BaseResponse
  22.                 .builder()
  23.                 .code(ResultCode.PARAM_TYPE_ERROR)
  24.                 .message(message)
  25.                 .build();
  26.     }
  28.     @ExceptionHandler(MethodArgumentNotValidException.class)
  29.     public BaseResponse handleError(MethodArgumentNotValidException e) {
  30.         logger.warn("Method Argument Not Valid", e);
  31.         BindingResult result = e.getBindingResult();
  32.         FieldError error = result.getFieldError();
  33.         String message = String.format("%s:%s", error.getField(), error.getDefaultMessage());
  34.         return BaseResponse
  35.                 .builder()
  36.                 .code(ResultCode.PARAM_VALID_ERROR)
  37.                 .message(message)
  38.                 .build();
  39.     }
  41.     @ExceptionHandler(BindException.class)
  42.     public BaseResponse handleError(BindException e) {
  43.         logger.warn("Bind Exception", e);
  44.         FieldError error = e.getFieldError();
  45.         String message = String.format("%s:%s", error.getField(), error.getDefaultMessage());
  46.         return BaseResponse
  47.                 .builder()
  48.                 .code(ResultCode.PARAM_BIND_ERROR)
  49.                 .message(message)
  50.                 .build();
  51.     }
  53.     @ExceptionHandler(ConstraintViolationException.class)
  54.     public BaseResponse handleError(ConstraintViolationException e) {
  55.         logger.warn("Constraint Violation", e);
  56.         Set<ConstraintViolation<?>> violations = e.getConstraintViolations();
  57.         ConstraintViolation<?> violation = violations.iterator().next();
  58.         String path = ((PathImpl) violation.getPropertyPath()).getLeafNode().getName();
  59.         String message = String.format("%s:%s", path, violation.getMessage());
  60.         return BaseResponse
  61.                 .builder()
  62.                 .code(ResultCode.PARAM_VALID_ERROR)
  63.                 .message(message)
  64.                 .build();
  65.     }
  67.     @ExceptionHandler(NoHandlerFoundException.class)
  68.     public BaseResponse handleError(NoHandlerFoundException e) {
  69.         logger.error("404 Not Found", e);
  70.         return BaseResponse
  71.                 .builder()
  72.                 .code(ResultCode.NOT_FOUND)
  73.                 .message(e.getMessage())
  74.                 .build();
  75.     }
  77.     @ExceptionHandler(HttpMessageNotReadableException.class)
  78.     public BaseResponse handleError(HttpMessageNotReadableException e) {
  79.         logger.error("Message Not Readable", e);
  80.         return BaseResponse
  81.                 .builder()
  82.                 .code(ResultCode.MSG_NOT_READABLE)
  83.                 .message(e.getMessage())
  84.                 .build();
  85.     }
  87.     @ExceptionHandler(HttpRequestMethodNotSupportedException.class)
  88.     public BaseResponse handleError(HttpRequestMethodNotSupportedException e) {
  89.         logger.error("Request Method Not Supported", e);
  90.         return BaseResponse
  91.                 .builder()
  92.                 .code(ResultCode.METHOD_NOT_SUPPORTED)
  93.                 .message(e.getMessage())
  94.                 .build();
  95.     }
  97.     @ExceptionHandler(HttpMediaTypeNotSupportedException.class)
  98.     public BaseResponse handleError(HttpMediaTypeNotSupportedException e) {
  99.         logger.error("Media Type Not Supported", e);
  100.         return BaseResponse
  101.                 .builder()
  102.                 .code(ResultCode.MEDIA_TYPE_NOT_SUPPORTED)
  103.                 .message(e.getMessage())
  104.                 .build();
  105.     }
  107.     @ExceptionHandler(ServiceException.class)
  108.     public BaseResponse handleError(ServiceException e) {
  109.         logger.error("Service Exception", e);
  110.         return BaseResponse
  111.                 .builder()
  112.                 .code(e.getResultCode())
  113.                 .message(e.getMessage())
  114.                 .build();
  115.     }
  117.     @ExceptionHandler(PermissionDeniedException.class)
  118.     public BaseResponse handleError(PermissionDeniedException e) {
  119.         logger.error("Permission Denied", e);
  120.         return BaseResponse
  121.                 .builder()
  122.                 .code(e.getResultCode())
  123.                 .message(e.getMessage())
  124.                 .build();
  125.     }
  127.     @ExceptionHandler(Throwable.class)
  128.     public BaseResponse handleError(Throwable e) {
  129.         logger.error("Internal Server Error", e);
  130.         return BaseResponse
  131.                 .builder()
  132.                 .code(ResultCode.INTERNAL_SERVER_ERROR)
  133.                 .message(e.getMessage())
  134.                 .build();
  135.     }
  136. }

最后封装返回给到前端BaseResponse

  1. @Data
  2. @NoArgsConstructor
  3. @AllArgsConstructor
  4. @Builder
  5. public class BaseResponse {
  6.     private String message;
  7.     @Builder.Default
  8.     private ResultCode code = ResultCode.SUCCESS;
  10.     public boolean isSuccess() {
  11.         return code == ResultCode.SUCCESS;
  12.     }
  13. }
  1. **
  2.  * Result Code Enum
  3.  *
  4.  * @author william
  5.  */
  6. @Getter
  7. @AllArgsConstructor
  8. public enum ResultCode {
  9.     SUCCESS(HttpServletResponse.SC_OK, "Operation is Successful"),
  11.     FAILURE(HttpServletResponse.SC_BAD_REQUEST, "Biz Exception"),
  13.     UN_AUTHORIZED(HttpServletResponse.SC_UNAUTHORIZED, "Request Unauthorized"),
  15.     NOT_FOUND(HttpServletResponse.SC_NOT_FOUND, "404 Not Found"),
  17.     MSG_NOT_READABLE(HttpServletResponse.SC_BAD_REQUEST, "Message Can't be Read"),
  19.     METHOD_NOT_SUPPORTED(HttpServletResponse.SC_METHOD_NOT_ALLOWED, "Method Not Supported"),
  21.     MEDIA_TYPE_NOT_SUPPORTED(HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE, "Media Type Not Supported"),
  23.     REQ_REJECT(HttpServletResponse.SC_FORBIDDEN, "Request Rejected"),
  25.     INTERNAL_SERVER_ERROR(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Internal Server Error"),
  27.     PARAM_MISS(HttpServletResponse.SC_BAD_REQUEST, "Missing Required Parameter"),
  29.     PARAM_TYPE_ERROR(HttpServletResponse.SC_BAD_REQUEST, "Parameter Type Mismatch"),
  31.     PARAM_BIND_ERROR(HttpServletResponse.SC_BAD_REQUEST, "Parameter Binding Error"),
  33.     PARAM_VALID_ERROR(HttpServletResponse.SC_BAD_REQUEST, "Parameter Validation Error");
  35.     final int code;
  37.     final String msg;
  38. }

mvc

对于springmvc, 比如web-app服务, 统一异常处理是实现ErrorController, 重写handleError方法, 并自定义error.html页面

补充: 也可以使用@ControllerAdvice

GlobalErrorController

  1. @Controller
  2. @SuppressWarnings(value = "Duplicates")
  3. public class GlobalErrorController implements ErrorController {
  5.     static final ILogger logger = SLoggerFactory.getLogger(GlobalErrorController.class);
  7.     @Autowired
  8.     ErrorPageFactory errorPageFactory;
  9.     @Autowired
  10.     SentryClient sentryClient;
  11.     @Autowired
  12.     StaffjoyProps staffjoyProps;
  13.     @Autowired
  14.     EnvConfig envConfig;
  16.     @Override
  17.     public String getErrorPath() {
  18.         return "/error";
  19.     }
  21.     @RequestMapping("/error")
  22.     public String handleError(HttpServletRequest request, Model model) {
  24.         Object statusCode = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
  25.         Object exception = request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
  27.         ErrorPage errorPage = null;
  28.         if (statusCode != null && (Integer)statusCode == HttpStatus.NOT_FOUND.value()) {
  29.             errorPage = errorPageFactory.buildNotFoundPage();
  30.         } else {
  31.             errorPage = errorPageFactory.buildInternalServerErrorPage();
  32.         }
  34.         if (exception != null) {
  35.             if (envConfig.isDebug()) {  // no sentry aop in debug mode
  36.                 logger.error("Global error handling", exception);
  37.             } else {
  38.                 sentryClient.sendException((Exception)exception);
  39.                 UUID uuid = sentryClient.getContext().getLastEventId();
  40.                 errorPage.setSentryErrorId(uuid.toString());
  41.                 errorPage.setSentryPublicDsn(staffjoyProps.getSentryDsn());
  42.                 logger.warn("Reported error to sentry", "id", uuid.toString(), "error", exception);
  43.             }
  44.         }
  46.         model.addAttribute(Constant.ATTRIBUTE_NAME_PAGE, errorPage);
  48.         return "error";
  49.     }
  51. }

error.html

  1. <!DOCTYPE html>
  2. <html lang=en
  3.       xmlns:th="http://www.thymeleaf.org">
  4. <meta charset=utf-8>
  5. <meta name=viewport content="initial-scale=1, minimum-scale=1, width=device-width">
  6. <title th:text="${page.title}" />
  7. <link href="https://fonts.googleapis.com/css?family=Open+Sans:300,400" rel="stylesheet">
  8. <style>
  9.     *{margin:0;padding:0}
  10.     html{
  11.         font-size: 15px;
  12.         font-family: 'Open Sans', sans-serif;
  13.         background: #f7f7f7;
  14.         padding:16px
  15.         width: 100%;
  16.     }
  17.     h1 {
  18.         font-size: 24px;
  19.         font-weight: 300;
  20.         letter-spacing: -1px;
  21.         color: #423a3f;
  22.         margin-top: 32px;
  23.     }
  24.     body{
  25.         width: 100%;
  26.         height: 100%;
  27.     }
  28.     p {
  29.         margin:11px 0 22px;
  30.         overflow:hidden
  31.         line-height: 1.75;
  32.         letter-spacing: normal;
  33.         text-align: center;
  34.         color: #423a3f;
  35.         margin-top: 12px;
  36.     }
  37.     a {
  38.         text-decoration: none;
  39.         font-size: 16px;
  40.         line-height: 1.75;
  41.         text-align: center;
  42.         color: #3daa9b;
  43.         margin-top: 32px;
  44.     }
  45.     #container {
  46.         padding: 20% 10%;
  47.         max-width: 80%;
  48.         width: 380;
  49.         text-align: center;
  50.         margin: 0 auto;
  51.     }
  52.     img {
  53.         width: 340px;
  54.         max-width: 100%;
  55.     }
  56. </style>
  57. <body>
  59. <div id="container">
  60.     <img th:src="|data:image/png;base64,${page.imageBase64}|" alt="Spilled Coffee" />
  61.     <h1 th:text="${page.title}" />
  62.     <p th:text="${page.explanation}" />
  63.     <p><a th:href="${page.linkHref}" th:text="${page.linkText}" /></p>
  64. </div>
  66. <th:block th:if="${page.sentryErrorId != null and page.sentryPublicDsn != null}">
  67. <script src="https://cdn.ravenjs.com/2.1.0/raven.min.js"></script>
  68. <script th:inline="javascript">
  69.     /*<![CDATA[*/
  70.     Raven.showReportDialog({
  71.         // grab the eventId generated by the Sentry SDK
  72.         eventId: /*[[${page.sentryErrorId}]]*/ '',
  73.         // use the public DSN (dont include your secret!)
  74.         dsn: /*[[${page.sentryPublicDsn}]]*/ ''
  75.     });
  76.     /*]]>*/
  77. </script>
  78. </th:block>
  79. </body>
  80. </html>

feign异常

老师，微服务内部调用feign接口抛出的异常，如何统一处理，需要捕获什么类型的异常？ 作者回复: 初步网上查了一下，一种统一处理feign接口异常的方法是：用RestControllerAdvice集中捕获和处理FeignException
参考：
https://stackoverflow.com/questions/55020389/spring-feign-client-exception-handling
https://www.javacodemonk.com/feign-exception-handling-spring-cloud-20d17f69

异常一般可以分为两类：
1. 底层http通讯异常，比如连不上或超时等
2. 服务端返回http错误码异常。

具体要根据应用场景分析。

DTO与DMO互转

可以都使用DMO或冗余DTO, 看项目选型, 课程使用modelmapper进行两者转换
一般项目有这两种就足够了, 保持风格一致性

  • DTO: 数据传输对象
  • DMO: 数据模型对象

mapping框架对比: https://www.baeldung.com/java-performance-mapping-frameworks
image.png

异步

使用springAsync来实现异步操作

首先定义个业务线程池

  1. @Configuration
  2. @EnableAsync
  3. @Import(value = {StaffjoyRestConfig.class})
  4. @SuppressWarnings(value = "Duplicates")
  5. public class AppConfig {
  7.     public static final String ASYNC_EXECUTOR_NAME = "asyncExecutor";
  9.     @Bean(name=ASYNC_EXECUTOR_NAME)
  10.     public Executor asyncExecutor() {
  11.         ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
  12.         // for passing in request scope context
  13.         executor.setTaskDecorator(new ContextCopyingDecorator());
  14.         executor.setCorePoolSize(3);
  15.         executor.setMaxPoolSize(5);
  16.         executor.setQueueCapacity(100);
  17.         executor.setWaitForTasksToCompleteOnShutdown(true);
  18.         executor.setThreadNamePrefix("AsyncThread-");
  19.         executor.initialize();
  20.         return executor;
  21.     }
  23.     @Bean
  24.     public PasswordEncoder passwordEncoder() {
  25.         return new BCryptPasswordEncoder();
  26.     }
  28. }

注意父子线程复制上下文

  1. // https://stackoverflow.com/questions/23732089/how-to-enable-request-scope-in-async-task-executor
  2. public class ContextCopyingDecorator implements TaskDecorator {
  3.     @Override
  4.     public Runnable decorate(Runnable runnable) {
  5.         RequestAttributes context = RequestContextHolder.currentRequestAttributes();
  6.         return () -> {
  7.             try {
  8.                 RequestContextHolder.setRequestAttributes(context);
  9.                 runnable.run();
  10.             } finally {
  11.                 RequestContextHolder.resetRequestAttributes();
  12.             }
  13.         };
  14.     }
  15. }

使用方式如下:

  • 使用@Async注解标注在异步方法上, 并指定对应的线程池
  • 注意异步方法与调用方不能在同一个bean中(AOP的限制) ```java @Service @RequiredArgsConstructor public class AccountService {

private final ServiceHelper serviceHelper;

  1.   public AccountDto create(String name, String email, String phoneNumber) {
  2.   ...
  3.       serviceHelper.syncUserAsync(account.getId());
  4.   ...
  5.   }

}

  1. ```java
  2. @RequiredArgsConstructor
  3. @Component
  4. public class ServiceHelper {
  6.     @Async(AppConfig.ASYNC_EXECUTOR_NAME)
  7.     public void syncUserAsync(String userId) {
  8.       ...
  9.     }
  10. }