Question

我正在使用Spring Boot 1.5.4与Spring JPA，Spring Data REST，HATEOAS ...... 我正在寻找最佳实践（Spring方式）来定制异常Spring Data REST正在管理添加i18n支持。

我将类MessageException（https://github.com/spring-projects/spring-data-rest/blob/master/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/support/ExceptionMessage.java）视为起点。

典型的Spring Data REST异常非常好：

    {
    "timestamp": "2017-06-24T16:08:54.107+0000",
    "status": 500,
    "error": "Internal Server Error",
    "exception": "org.springframework.dao.InvalidDataAccessApiUsageException",
    "message": "org.hibernate.TransientPropertyValueException: Not-null property references a transient value - transient instance must be saved beforeQuery current operation : com.test.server.model.workflows.WorkSession.checkPoint -> com.test.server.model.checkpoints.CheckPoint; nested exception is java.lang.IllegalStateException: org.hibernate.TransientPropertyValueException: Not-null property references a transient value - transient instance must be saved beforeQuery current operation : com.test.server.model.workflows.WorkSession.checkPoint -> com.test.server.model.checkpoints.CheckPoint",
    "path": "/api/v1/workSessions/start"
}

我要做的是：

本地化错误和消息字段（i18n）
可能会将消息文本更改为其他内容（始终本地化）

我没有在Spring Data REST文档中找到有关如何自定义或本地化异常（https://docs.spring.io/spring-data/rest/docs/current/reference/html/）的任何参考。我希望有一种优雅的方式来做到这一点。

我在我的WebMvcConfigurerAdapter中添加了这个：

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

public class SmartLocaleResolver extends CookieLocaleResolver {

    @Override
    public Locale resolveLocale(HttpServletRequest request) {
        String acceptLanguage = request.getHeader("Accept-Language");
        if (acceptLanguage == null || acceptLanguage.trim().isEmpty()) {
            return super.determineDefaultLocale(request);
        }
        return request.getLocale();
    }

}

@Bean
public ResourceBundleMessageSource messageSource() {
    ResourceBundleMessageSource source = new ResourceBundleMessageSource();
    source.setBasenames("i18n/messages"); // name of the resource bundle
    source.setUseCodeAsDefaultMessage(true);
    return source;
}

我想我能够以这种方式拦截异常：

    @ControllerAdvice(annotations = RepositoryRestController.class)
public class GenericExceptionHandler {

    @ExceptionHandler
    public ResponseEntity handle(Exception e, Locale locale) {
          //missing part...
            return new ResponseEntity(exceptionMessageObject, new HttpHeaders(), httpStatus);
    }

有没有办法使用Spring最佳实践将所有内容组合在一起？

Answer 1

@ControllerAdvice(annotations = RepositoryRestController.class)
public class GenericExceptionHandler {
    @Autowired
    private MessageSource messageSource;

    @ExceptionHandler
    //if you don't use Exception e in method you can remove it , live only Locale
    public ResponseEntity handle(Exception e, Locale locale) {

            String errorMessage = messageSource.getMessage(
                                 "error.message", new Object[]{},locale);  
            //set message  or return it instead of exceptionMessageObject
            exceptionMessageObject.setMessage(exceptionMessageObject);

            return new ResponseEntity(exceptionMessageObject, 
                   new HttpHeaders(), httpStatus);
    }

请参阅spring doc 7.15.1 Internationalization using MessageSource

“我应该如何创建exceptionMessageObject，就像一个Spring 数据REST创建？ “

创建自己的错误包装器，如：

public class CustomError {
    private HttpStatus status;
    private String message;
    private Exception originalException;//if you need it        
    // getter setter
}

“如何为不同的例外提供不同的信息？我应该创建一个long if else链来检查异常的类？ “

创建解析器，

private String resolveExceptionToMessage(Exception exceptio){
    //or put in map<Exceptio,String error.message.type1> 
    // String errorCode = map.get(excptio);
    //eturn messageSource.getMessage(errorCode , new Object[]{},locale);
    if(exceptio instanceof ....){
        return messageSource.getMessage("error.message.type1", new Object[]{},locale);
    }
    return "";
}

或者使用带有@ExceptionHandler（{CustomException1.class}），@ ExceptionHandler（{CustomException1.class}）的方法....并且在每个方法中放入errror.code，所有其他部分都是相似的

 @ExceptionHandler({ CustomException1.class})
    public ResponseEntity handleException1() {
        return createError(code for this exceptio 1);
    }
    @ExceptionHandler({ CustomException2.class})
    public ResponseEntity handleException2() {
        return createError(code for this exceptio 2);
    }
    private ResponseEntity createError(String errorCode ) {
            CustomError customError = new CustomError();
            customError.setHttpStatus(HttpStatus.BAD_REQUEST);
            String errorMessage = messageSource.getMessage(
                                 errorCode , new Object[]{},locale); 

            customError.setMessage(errorMessage );
            customError.setOriginalException(e);
            return new ResponseEntity<Object>(customError, new HttpHeaders(), 
                          customError.getStatus());
    }

如何设置httpStatus？我想使用默认状态Spring Data REST用于公共异常...

public ResponseEntity handle(Exception e, Locale locale) {
        CustomError customError = new CustomError();
        customError.setHttpStatus(HttpStatus.BAD_REQUEST);
        customError.setMessage(resolveExceptionToMessage(e));
        customError.setOriginalException(e);
        return new ResponseEntity<Object>(customError, new HttpHeaders(), 
                      customError.getStatus());
}

Answer 2

感谢@sbjavateam的回复。为了完整起见，我想发布另一种做这件事的方法。评论并不适合写一切，所以我在这里回复。

使用@ControllerAdvice，更简单的解决方案是自定义ErrorAttributes：

public class CustomErrorAttributes extends DefaultErrorAttributes {

    private Logger log = LogManager.getLogger();

    @Autowired
    private MessageSource messageSource;

    @Override
    public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
        Locale locale = LocaleContextHolder.getLocale();
        Map<String, Object> errorAttributes = super.getErrorAttributes(requestAttributes, includeStackTrace);
        Throwable throwable = getError(requestAttributes);

        /**
         * Adding the cause if present
         */
        if (throwable != null && throwable.getCause() != null) {
            Throwable cause = throwable.getCause();
            Map<String, Object> causeErrorAttributes = new HashMap<>();
            causeErrorAttributes.put("exception", cause.getClass().getName());
            causeErrorAttributes.put("message", cause.getMessage());
            errorAttributes.put("cause", causeErrorAttributes);
        }

        /**
         * Customizing the message for every exception
         */
        if (throwable instanceof InvalidDataAccessApiUsageException) {
            String message = messageSource.getMessage(throwable.getClass().getName(), new Object[] {}, locale);
            errorAttributes.put("message", message);
        }
        return errorAttributes;
    }
}

当然，您必须在WebMvcConfigurerAdapter中定义此bean或添加@Component。在第一种情况下，你需要做：

@EnableHypermediaSupport(type = { HypermediaType.HAL })
public class WebMvcConfiguration extends WebMvcConfigurerAdapter {

    @Bean
    public CustomErrorAttributes myCustomErrorAttributes() {
        return new CustomErrorAttributes();
    }

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasenames("classpath:/i18n/messages");
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setUseCodeAsDefaultMessage(true);
        messageSource.setCacheSeconds((int) TimeUnit.HOURS.toSeconds(1));
        messageSource.setFallbackToSystemLocale(false);
        return messageSource;
    }
}

通过这种方式可以非常轻松地自定义异常，您只需覆盖值，而不是创建新的自定义异常对象。

Answer 3

在我的项目中，我使用CustomErrorController。该控制器缓存所有错误，包括404。示例：

@Controller
@RequestMapping("${error.path:/error}")
public class CustomErrorController implements ErrorController {

@Value("${error.path:/error}")
private String errorPath;

@Override
public String getErrorPath() {
    return this.errorPath;
}

@RequestMapping
@ResponseBody
public ResponseEntity<Object> error(HttpServletRequest request) {
    HashMap<String, Object> response = new HashMap<String, Object>();
    // your code here...
    return new ResponseEntity<Object>(response, status);
}
}

使用Spring Data REST处理自定义异常（i18n）

3 个答案: