java - 根据 Spring Boot 中的 Accept-Language 检索语言环境

Question

我有一个 Spring Boot (2.1.3.RELEASE) 应用程序，它使用 Jersey 来定义 (RESTful) 端点。我正在尝试根据用户代理发送的区域设置来读取和传播一些消息。

我已经配置了这些 bean:

@Bean
public LocaleResolver localeResolver() {
  final AcceptHeaderLocaleResolver resolver = new AcceptHeaderLocaleResolver();
  resolver.setSupportedLocales(Arrays.asList(Locale.GERMANY, Locale.US));
  resolver.setDefaultLocale(Locale.ENGLISH);
  return resolver;
}

@Bean
public MessageSource messageSource() { // Not sure if this is needed
  final ReloadableResourceBundleMessageSource messageSource = new ReloadableResourceBundleMessageSource();
  messageSource.setDefaultEncoding(StandardCharsets.UTF_8.name());
  messageSource.setBasenames("classpath:/messages");
  messageSource.setUseCodeAsDefaultMessage(true);
  messageSource.setCacheSeconds(5);
  return messageSource;
}

...还有 bundle (在 ../src/main/resources/ 内)，例如:messages.properties(后备)、messages_en_US。属性、messages_de_DE.properties等

现在，挑战是我不确定如何“读取”用户代理发送的区域设置，以便正确读取包中的消息。我正在注入(inject) MessageSource ms，并以编程方式读取消息，例如:

final Locale locale = ???
ms.getMessage("message.duplicate-token", null, locale);

有什么线索吗？

I've tried LocaleContextHolder.getLocale() but it's always en_US. If I hardcode the corresponding locale for the getMessage call, I'm able to retrieve the correct message(s). So I know the setup/configuration works for the most part.

<小时/>

客户端使用 Accept-Language header 发送区域设置 - 以及诸如:de-DE、en-US 等值。

Answer 1

您需要添加一个 LocaleChangeInterceptor 并配置 bean，如下所示:请参阅Spring Boot internationalization了解更多

@Bean
public LocaleChangeInterceptor localeChangeInterceptor() {
    LocaleChangeInterceptor lci = new LocaleChangeInterceptor();
    lci.setParamName("lang");
    return lci;
}

如果您只想使用“Accept-Language” header ，那么您可以扩展 AcceptHeaderLocaleResolver 并可以自定义:

package com.deb.demo.config;

import java.util.Arrays;
import java.util.List;
import java.util.Locale;

import javax.servlet.http.HttpServletRequest;

import org.springframework.util.StringUtils;
import org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;

public class CustomLocaleResolver extends AcceptHeaderLocaleResolver {


    List<Locale> LOCALES = Arrays.asList(new Locale("en"),new Locale("es"),new Locale("fr"));


  @Override
  public Locale resolveLocale(HttpServletRequest request) {
     if (StringUtils.isEmpty(request.getHeader("Accept-Language"))) {
         return Locale.getDefault();
       }
     List<Locale.LanguageRange> list = Locale.LanguageRange.parse(request.getHeader("Accept-Language"));
     Locale locale = Locale.lookup(list,LOCALES);
      return locale;
     }
}