基于请求URL的国际化实现方式

用户1418372

发布于 2019-02-25 11:25:57

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发布于 2019-02-25 11:25:57

文章被收录于专栏：清晨我上码清晨我上码

基于请求URL的国际化实现方式

原理：使用spring的request bean保存相应的国际化组件，这样保证同一个请求的国际化相同，也是在微服务处理国际化的一种方式。需要针对每个请求做不同的国际化

实现所以需要，相应的拦截器去处理对应请求域中的国际化组件

配置文件：

spring容器配置applicationContext.xml，中添加取得信息的messageSource，放在spring容器而非springmvc容器加载是因为代码中有Service的注解依赖于他

<!-- 国际换的service依赖于他，所以从mvc提到前面 -->
    <bean id="messageSource"
        class="org.springframework.context.support.ResourceBundleMessageSource">
        <!-- 国际化信息所在的文件名 -->
        <property name="basename" value="messages/messages" />
        <property name="defaultEncoding" value="UTF-8"/> 
        <!-- 如果在国际化资源文件中找不到对应代码的信息，就用这个代码作为名称 -->
        <property name="useCodeAsDefaultMessage" value="true" />
    </bean>

springmvc容器配置拦截器，注意拦截器的顺序，国际化的拦截器在处理请求的拦截器前面

<mvc:interceptors>
       <mvc:interceptor>  
      <mvc:mapping path="/**"/>  
       <!-- 国际化操作拦截器 如果采用基于（请求/Session/Cookie）则必需配置 --> 
      <bean  id="localeChangeInterceptor"
               class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
          <property name="paramName" value="locale"/>
      </bean>
      </mvc:interceptor>  
      <mvc:interceptor>
          <!-- 需拦截的地址 -->
          <!--   级目录 -->
          <mvc:mapping path="/*" />
          <mvc:mapping path="/*/*" />
          <!-- 需排除拦截的地址 -->
          <mvc:exclude-mapping path="/*.html"/>
          <bean class="cn.xx.xx.xx.interceptor.ControllerInterceptor" />
      </mvc:interceptor>
  </mvc:interceptors>
  <!-- 基于url的国际化 id必须为localeResolver否则国际化组件无法识别，UrlAcceptHeaderLocaleResolver为自定义实现部分-->
<bean id="localeResolver" class="cn.abcsys.devops.application.service.UrlAcceptHeaderLocaleResolver"/>

UrlAcceptHeaderLocaleResolver作为localeResolver国际urlLocal

/**
* Copyright: Copyright (c) 2018 LanRu-Caifu
* @author xzg
* 2018年2月6日
* @ClassName: UrlAcceptHeaderLocaleResolver.java
* @Description: 国际化拦截请求后对请求更改Local
* @version: v1.0.0
*/
public class UrlAcceptHeaderLocaleResolver extends AcceptHeaderLocaleResolver {

   private Locale urlLocal;

   public Locale resolveLocale(HttpServletRequest request) {
       
       return urlLocal != null?urlLocal:request.getLocale();
   } 
   @Override
   public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
       urlLocal = locale;
   }
}

spring中的request bean依赖于接口实现，下面是其接口和对应的实现类

public interface I18nSessionService {
  
  public void setRc(RequestContext rc);
  
  public void setRcByRequest(HttpServletRequest request);
  
  public String getMessage(String key); 
  
  public String getMessage(String key,Object info);
  
  public String getMessage(String key,Object...objects);
}

下面注解主要为设置作用域为request，注入messageSource组件，并提供RequestContext用于切换语言配置国际化

@Component
@RequestScope(proxyMode = ScopedProxyMode.INTERFACES)
public class I18nSessionServiceImpl implements I18nSessionService {

  @Autowired  
  @Qualifier("messageSource")  
  private MessageSource resources;
  //前端设置切换语言是设置
  private RequestContext rc ;
  
  public RequestContext getRc() {
      return rc;
  }
  @Override
  public void setRcByRequest(HttpServletRequest request) {
      // TODO Auto-generated method stub
      this.rc = new RequestContext(request);
  }
  
  @Override
  public void setRc(RequestContext rc) {
      this.rc = rc;
  }

  @Override
  public String getMessage(String key) {
      // TODO Auto-generated method stub
      if(null != getRc()){
          return getRc().getMessage(key);
      }
      return resources.getMessage(key, null, null);
  }

  @Override
  public String getMessage(String key, Object info) {
      // TODO Auto-generated method stub
      if(null != getRc()){
          return getRc().getMessage(key, new Object[]{info});
      }
      return resources.getMessage(key, new Object[]{info}, null);
  }

  @Override
  public String getMessage(String key, Object... objects) {
              if(null != getRc()){
                  return getRc().getMessage(key, objects);
              }
              return resources.getMessage(key, objects, null);
  }
}

自定义的拦截器中处理，国际化组件的请求bean

@Component
public class ControllerInterceptor implements HandlerInterceptor {
  /**
   * 在Controller方法前进行拦截
   */
  @Resource
  private I18nSessionService  i18nSessionService;
  private static Logger log = Logger.getLogger("ControllerInterceptor");
  public boolean preHandle(HttpServletRequest request,
                           HttpServletResponse response, Object handler) throws Exception {
      log.info("RequestURI :"+request.getRequestURI());
      //解决跨域
      response.setHeader("Access-Control-Allow-Origin", "*");
      response.setHeader("Access-Control-Allow-Methods","POST");
      response.setHeader("Access-Control-Allow-Headers","x-requested-with,content-type");
      //拦截器中对所有的请求处理，保存到request bean中
      i18nSessionService.setRcByRequest(request);
      return true;
  }

  public void postHandle(HttpServletRequest request,
                         HttpServletResponse response, Object handler,
                         ModelAndView modelAndView) throws Exception {
  }
  /**
   * 在Controller方法后进行拦截
   */
  public void afterCompletion(HttpServletRequest request,
                              HttpServletResponse response, Object handler, Exception ex)
          throws Exception {
  }
}

使用方式

//发送请求 http://localhost:8080/testI18n.do?locale=en_US 或者http://localhost:8080/testI18n.do?locale=zh_CN
@Resource
private I18nSessionService is;
@RequestMapping(value = "/testI18n.do", method = { RequestMethod.POST,RequestMethod.GET})
public @ResponseBody
   Result testI18n(){
       return new Result(true, is.getMessage("argument.required"), "");
}