Spring REST处理区域设置更改

Question

我正在尝试在Spring 3 REST应用程序中处理区域设置更改.

但是语言环境没有改为fr.

控制台日志显示:2014-05-19 14:29:46,214 DEBUG [AbstractExceptionHandler] locale:en

这是我的配置:

    @Bean
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
        messageSource.setBasenames("classpath:messages/messages", "classpath:messages/validation");
        // 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(0);
        return messageSource;
    }

    // The locale interceptor provides a way to switch the language in any page just by passing the lang=’en’, lang=’fr’, and so on to the url
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
        localeChangeInterceptor.setParamName("lang");
        registry.addInterceptor(localeChangeInterceptor);
    }

    @Bean
    public LocaleResolver localeResolver() {
        CookieLocaleResolver localeResolver = new CookieLocaleResolver();
        localeResolver.setDefaultLocale(new Locale("en"));
        return localeResolver;
    }

这是我的异常处理程序:

@ControllerAdvice
public class AdminExceptionHandler extends AbstractExceptionHandler {

    @ExceptionHandler(NullPointerException.class)
    @ResponseBody
    public ResponseEntity<ErrorInfo> nullPointerException(HttpServletRequest request, NullPointerException e) {
        String url = request.getRequestURL().toString();
        String errorMessage = localizeErrorMessage("error.npe", new Object[] { e.getMessage() });
        return new ResponseEntity<ErrorInfo>(new ErrorInfo(url, errorMessage), HttpStatus.INTERNAL_SERVER_ERROR);
    }

}

public class AbstractExceptionHandler {

    private static Logger logger = LoggerFactory.getLogger(AbstractExceptionHandler.class);

    @Autowired
    private MessageSource messageSource;

    protected String localizeErrorMessage(String errorCode, Object args[]) {
        Locale locale = LocaleContextHolder.getLocale();
        logger.debug("locale: " + locale);
        return messageSource.getMessage(errorCode, args, locale);
    }

    protected String localizeErrorMessage(String errorCode) {
        return localizeErrorMessage(errorCode, null);
    }

    protected String extractAdminIdFromUrl(String url) {
        String adminId = null;
        try {
            URI uri = new URI(url);
            String path = uri.getPath();
            adminId = path.substring(path.lastIndexOf('/') + 1);
        } catch (URISyntaxException e1) {
            e1.printStackTrace();
        }
        return adminId;
    }

}

这是我的测试:

@Test
public void testExceptionLocalizedMessage() throws Exception {
    HttpHeaders httpHeaders = Common.createAuthenticationHeaders("stephane" + ":" + PASSWORD);

    MvcResult resultGet = this.mockMvc.perform(
            get("/error/npe").headers(httpHeaders)
            .param("lang", "fr")
            .accept(MediaType.APPLICATION_JSON)
        )
        .andExpect(status().isInternalServerError())
        .andExpect(jsonPath("$.message").value("Une erreur inconnue s'est produite. Veuillez nous excuser."))
        .andReturn();

    httpHeaders.add("Accept-Language", "fr");
    resultGet = this.mockMvc.perform(
            get("/error/npe").headers(httpHeaders)
            .accept(MediaType.APPLICATION_JSON)
        )
        .andExpect(status().isInternalServerError())
        .andExpect(jsonPath("$.message").value("Une erreur inconnue s'est produite. Veuillez nous excuser."))
        .andReturn();
}

我想处理url中的locale参数,如？lang = en和Accept-Language标题作为后退.

作为REST应用程序,我考虑使用AcceptHeaderLocaleResolver类,但它不支持通过url参数设置语言环境.

我估计在REST应用程序中使用SessionLocaleResolver类没什么意义.

这使我得到了CookieLocaleResolver类,我并不特别相信它是应该在REST应用程序中使用的类.

无论如何,检索到的语言环境仍然是en而不是我期望的那样.

编辑:

在测试中,使用语句:

httpHeaders.add("Accept-Language", Locale.FRENCH.getLanguage());

不设置区域设置.但是使用locale()可以.该测试通过:

this.mockMvc.perform(
        get("/error/npe").headers(httpHeaders).locale(Locale.FRENCH)
        .accept(MediaType.APPLICATION_JSON))
        .andDo(print()
    )
    .andExpect(status().isInternalServerError())
    .andExpect(jsonPath("$.message").value(localizeErrorMessage("error.npe", Locale.FRENCH)))
    .andReturn();

Answer 1

我找到了解决方案.现在正在使用Accept-Language标头和cookie.

public class WebConfiguration extends WebMvcConfigurerAdapter {

    @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();
    }

}

更新:在Thor的评论之后,这是一个首先检查cookie的解析器,如果没有找到,则检查请求头:

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

或者使用更简单的实现(未测试):

private AcceptHeaderLocaleResolver acceptHeaderLocaleResolver = new AcceptHeaderLocaleResolver();

@Override
public Locale resolveLocale(HttpServletRequest request) {
    Locale locale = super.determineDefaultLocale(request);
    if (null == locale) {
        locale = acceptHeaderLocaleResolver.resolveLocale(request);
    }
    return locale;
}

更新:以上解决方案不再有效.

我现在正试图在标题中传递接受的语言:

httpHeaders.add(HttpHeaders.ACCEPT_LANGUAGE, "fr_FR");

并在此语言环境解析器中检索它:

@Override
public Locale resolveLocale(HttpServletRequest request) {
    for (String httpHeaderName : Collections.list(request.getHeaderNames())) {
        logger.debug("===========>> Header name: " + httpHeaderName);
    }
    String acceptLanguage = request.getHeader(HttpHeaders.ACCEPT_LANGUAGE);
    logger.debug("===========>> acceptLanguage: " + acceptLanguage);
    Locale locale = super.resolveLocale(request);
    logger.debug("===========>> acceptLanguage locale: " + locale.getDisplayCountry());
    if (null == locale) {
        locale = getDefaultLocale();
        logger.debug("===========>> Default locale: " + locale.getDisplayCountry());
    }
    return locale;
}

但是记录器Accept-Language的输出中没有===========>> Header name,并且acceptLanguage记录器是空的.