Spring Boot 异常处理

Question

我们正在为我们的应用程序使用 Spring Boot。当基于 Accept-Language 标头调用 Rest 服务时，我试图在响应中返回本地化结果。例如，如果 Accept-Language 标头是：zh,ja;q=0.8,en。既然我们支持，那么回复将是中文的。

但如果 Accept-Language 标头是：zh1,ja;q=0.8,en。然后我得到如下所示的内部服务器错误，因为它无法调用@ExceptionHandler 我没有得到我喜欢的响应。以下是我得到的

{
  "timestamp": 1462213062585,
  "status": 500,
  "error": "Internal Server Error",
  "exception": "java.lang.IllegalArgumentException",
  "message": "java.lang.IllegalArgumentException: range=zh1",
  "path": "/user/v1//paymentmethods/creditdebitcards"
}

相反，这是我想要抛出的，因为对于所有其他异常，我们会处理并抛出类似的响应。

{
  "operation": {
    "result": "ERROR",
    "errors": [
      {
        "code": "1000",
        "message": "An unidentified exception has occurred.",
        "field": ""
      }
    ],
    "requestTimeStampUtc": "2016-05-02T18:22:03.356Z",
    "responseTimeStampUtc": "2016-05-02T18:22:03.359Z"
  }
}

以下是我的类，如果标题错误（如 zh1,ja;q=0.8,en），则下面的 parse 方法会像上面一样抛出 500 错误。

public class SmartLocaleResolver extends AcceptHeaderLocaleResolver {

    @Autowired
    ExceptionHandling exceptionHandling;

    @Autowired
    MessageHandler    messageHandler;

    @Override
    public Locale resolveLocale(HttpServletRequest request) {
        try {
            List<LanguageRange> list = Locale.LanguageRange.parse(request.getHeader("Accept-Language"));
            if (!list.isEmpty()) {
                for (LanguageRange s : list) {
                    if (ApplicationConstants.LOCALE.contains(s.getRange())) {
                        return Locale.forLanguageTag(s.getRange());
                    }
                }
            }
        } catch (IllegalArgumentException e) {
            throw new IllegalArgumentException(e);
        }
        return request.getLocale();
    }

下面是ExceptionHandler类

@EnableWebMvc
@ControllerAdvice
public class ExceptionHandling extends ResponseEntityExceptionHandler {
    private static final Logger LOGGER = LoggerFactory.getLogger(ExceptionHandling.class);

    @Autowired
    private MessageHandler      messageHandler;

    @ResponseStatus(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
    @ExceptionHandler(value = { UnsupportedMediaTypeException.class, InvalidMediaTypeException.class })
    public void unsupportedMediaTypeException() {

    }

    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    @ExceptionHandler(value = Exception.class)
    public @ResponseBody OperationsErrorBean handleglobalException(final HttpServletRequest request,
            final Exception ex) {
        LOGGER.error("Unhandled Exception Occurred: ", ex);
        return errorResponse("1000", messageHandler.localizeErrorMessage("error.1000"), "", request.getRequestURI(),
                request.getAttribute("startTime").toString());

    }
}

这是我的 ApplicationConfig.java 类

@Configuration
@ComponentScan("com.hsf")
@EnableWebMvc
public class ApplicationConfig extends WebMvcConfigurerAdapter {

    @Value("${spring.application.name}")
    String appName;

    @Bean
    public AlwaysSampler defaultSampler() {
        return new AlwaysSampler();
    }

    @Override
    public void addInterceptors(final InterceptorRegistry registry) {

        if (StringUtils.isNotBlank(appName)) {
            MDC.put("AppName", appName);

        } else {
            MDC.put("AppName", "APPNAME_MISSING");
        }

        registry.addInterceptor(new RequestInterceptor()).addPathPatterns("/user/v1/**");
    }

    @Bean
    public LocaleResolver localeResolver() {
        return new SmartLocaleResolver();
    }

    @Bean
    public DispatcherServlet dispatcherServlet() {
        final DispatcherServlet servlet = new DispatcherServlet();
        servlet.setDispatchOptionsRequest(true);
        return servlet;
    }

    @Bean
    public MessageSource messageSource() {
        final ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasenames("classpath:i18n/messages");
        // If true, the key of the message will be displayed if the key is not
        // found, instead of throwing an exception
        messageSource.setUseCodeAsDefaultMessage(true);
        messageSource.setDefaultEncoding("UTF-8");
        // The value 0 means always reload the messages to be developer friendly
        messageSource.setCacheSeconds(10);
        return messageSource;
    }

}

Answer 1

unsupportedMediaTypeException方法的@ExceptionHandler注解不包含IllegalArgumentException，而是：

@ResponseStatus(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
@ExceptionHandler(value = { UnsupportedMediaTypeException.class, 
  InvalidMediaTypeException.class })
public void unsupportedMediaTypeException() { }

应该是：

@ResponseStatus(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
@ExceptionHandler(value = { UnsupportedMediaTypeException.class, 
  InvalidMediaTypeException.class, IllegalArgumentException.class })
public void unsupportedMediaTypeException() { }

此外，由于处理多种语言似乎是您的应用程序的要求之一，我建议为这种情况创建一个专用的 RuntimeException InvalidAcceptLanguageException，而不是为此使用通用的 IllegalArgumentException。

Answer 2

我在拦截器中进行了 Accept-Language 检查，并在解析标头时抛出了我创建的自定义异常。所以我抛出了一个 400 Bad 请求，并给出了我想要显示的正确响应。

 public class RequestInterceptor extends HandlerInterceptorAdapter {
            @Override
            public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
                    throws Exception {

                final String startTime = DateUtils.getUTCDate();

                request.setAttribute("startTime", startTime);


                **try {
                    Locale.LanguageRange.parse(request.getHeader("Accept-Language"));
                } catch (IllegalArgumentException e) {
                    throw new InvalidAcceptLanguageException();
                }**

                return true;

            }
        }

我在我的 ExceptionHandling 类中添加了一个方法来抛出 InvalidAcceptLanguageException。

@EnableWebMvc
@ControllerAdvice
public class ExceptionHandling extends ResponseEntityExceptionHandler {
    private static final Logger LOGGER = LoggerFactory.getLogger(ExceptionHandling.class);


    @ResponseStatus(HttpStatus.BAD_REQUEST)
    @ExceptionHandler(value = InvalidAcceptLanguageException.class)
    @ResponseBody
    public OperationsErrorBean invalidAcceptLanguageException(final HttpServletRequest request, final Exception ex) {
        return errorResponse("N/A", "Accept-Language is not in correct format", "", request.getRequestURI(),
                request.getAttribute("startTime").toString());
    }
}