控制器 HttpServletRequest 语言环境不会改变

Question

当我通过请求参数更改首选语言时，网页中的语言会发生变化（使用 检索消息<spring:message code="xxxx"/>）但控制器中的区域设置不会更改，例如：

private void simpleControllerMethod(HttpServletRequest request, HttpServletResponse response, ModelAndView model) {
        System.out.println(request.getLocale().toString()); // prints default application locale no matter what
    }

dispather-servlet.xml 包含：

<bean id="messageSource"
    class="org.springframework.context.support.ResourceBundleMessageSource">
    <property name="basename">
        <value>messages</value>
    </property>
    <property name="defaultEncoding" value="UTF-8" />
    <property name="fallbackToSystemLocale" value="false" />
</bean>

<bean id="localeResolver"
    class="org.springframework.web.servlet.i18n.CookieLocaleResolver">
    <property name="defaultLocale" value="lt" />
    <property name="cookieName" value="lang" />
    <property name="cookieMaxAge" value="3600"/>
</bean>

<mvc:interceptors>  
    <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
          <property name="paramName" value="lang"></property>
    </bean>
</mvc:interceptors>

为什么 HttpServletRequest 的语言环境不会改变？

Answer 1

HttpServletRequest.getLocale() doesn't give you current locale. It gives you the preferred (preferred by the browser -judging from the header). If you want to get current locale you have to pass the Locale through method parameter:

private void simpleControllerMethod(HttpServletRequest request, HttpServletResponse response, ModelAndView model,Locale locale) {
    System.out.println(locale);
}

or just get Locale from static holder: LocaleContextHolder.getLocale()