Locale

Spring 架构的大多数部分都支持国际化，就像 Spring Web MVC 框架所做的那样。DispatcherServlet 允许使用客户端语言环境自动解析消息。这可以通过 LocaleResolver 对象实现。

Most parts of Spring’s architecture support internationalization, as the Spring web MVC framework does. DispatcherServlet lets you automatically resolve messages by using the client’s locale. This is done with LocaleResolver objects.

当一个请求到来时，DispatcherServlet 会寻找一个语言环境解析器，如果找到了一个，它会尝试使用它来设置语言环境。通过使用 RequestContext.getLocale() 方法，你始终可以检索由语言环境解析器解析的语言环境。

When a request comes in, the DispatcherServlet looks for a locale resolver and, if it finds one, it tries to use it to set the locale. By using the RequestContext.getLocale() method, you can always retrieve the locale that was resolved by the locale resolver.

除了自动区域设置解析外，还可以将拦截器附加到处理程序映射（有关处理程序映射拦截器的更多信息，请参阅Interception）以在特定情况下更改区域设置（例如，基于请求中的某个参数）。

In addition to automatic locale resolution, you can also attach an interceptor to the handler mapping (see Interception for more information on handler mapping interceptors) to change the locale under specific circumstances (for example, based on a parameter in the request).

语言环境解析器和拦截器在 org.springframework.web.servlet.i18n 包中定义，以一般的方式在你的应用程序上下文中进行配置。Spring 中包含了以下范围的语言环境解析器。

Locale resolvers and interceptors are defined in the org.springframework.web.servlet.i18n package and are configured in your application context in the normal way. The following selection of locale resolvers is included in Spring.

Time Zone

除了获取客户端的区域设置外，通常了解其时区也很有用。LocaleContextResolver 接口提供对 LocaleResolver 的扩展，它使得解析器能够提供一个更丰富的 LocaleContext，其中可能包括时区信息。

In addition to obtaining the client’s locale, it is often useful to know its time zone. The LocaleContextResolver interface offers an extension to LocaleResolver that lets resolvers provide a richer LocaleContext, which may include time zone information.

如果有，可以使用 RequestContext.getTimeZone() 方法获取用户的 TimeZone。时区信息由向 Spring 的 ConversionService 注册的任何 Date/Time Converter 和 Formatter 对象自动使用。

When available, the user’s TimeZone can be obtained by using the RequestContext.getTimeZone() method. Time zone information is automatically used by any Date/Time Converter and Formatter objects that are registered with Spring’s ConversionService.

Header Resolver

此语言环境解析器检查客户端发送的请求中的 accept-language 标头（例如，Web 浏览器）。通常，此标头字段包含客户端操作系统的语言环境。请注意，此解析器不支持时区信息。

This locale resolver inspects the accept-language header in the request that was sent by the client (for example, a web browser). Usually, this header field contains the locale of the client’s operating system. Note that this resolver does not support time zone information.

此语言环境解析器检查客户端上可能存在的 Cookie，以查看是否指定了 Locale 或 TimeZone。如果是，它将使用指定的信息。通过使用此语言环境解析器的属性，你可以指定 cookie 的名称以及 maximum age。以下示例定义了一个 CookieLocaleResolver：

This locale resolver inspects a Cookie that might exist on the client to see if a Locale or TimeZone is specified. If so, it uses the specified details. By using the properties of this locale resolver, you can specify the name of the cookie as well as the maximum age. The following example defines a CookieLocaleResolver:

<bean id="localeResolver" class="org.springframework.web.servlet.i18n.CookieLocaleResolver">

	<property name="cookieName" value="clientlanguage"/>

	<!-- in seconds. If set to -1, the cookie is not persisted (deleted when browser shuts down) -->
	<property name="cookieMaxAge" value="100000"/>

</bean>

下表描述了属性 CookieLocaleResolver：

The following table describes the properties CookieLocaleResolver:

Session Resolver

SessionLocaleResolver 允许你从可能与用户的请求关联的会话中检索 Locale 和 TimeZone。与 CookieLocaleResolver 相反，此策略将本地选择的语言环境设置存储在 Servlet 容器的 HttpSession 中。因此，这些设置对于每个会话都是临时的，并且因此在每个会话结束时都会丢失。

The SessionLocaleResolver lets you retrieve Locale and TimeZone from the session that might be associated with the user’s request. In contrast to CookieLocaleResolver, this strategy stores locally chosen locale settings in the Servlet container’s HttpSession. As a consequence, those settings are temporary for each session and are, therefore, lost when each session ends.

请注意，与外部会话管理机制（例如 Spring Session 项目）没有直接关系。此 SessionLocaleResolver 根据当前的 HttpServletRequest 评估和修改相应的 HttpSession 属性。

Note that there is no direct relationship with external session management mechanisms, such as the Spring Session project. This SessionLocaleResolver evaluates and modifies the corresponding HttpSession attributes against the current HttpServletRequest.

Locale Interceptor

你可以通过将 LocaleChangeInterceptor 添加到其中一个 HandlerMapping 定义来启用语言环境的更改。它检测请求中的参数并相应地更改语言环境，从而在分发器的应用程序上下文中对 LocaleResolver 调用 setLocale 方法。以下示例表明，所有包含名为 siteLanguage 的参数的 *.view 资源的调用现在都会更改语言环境。所以，例如，对 URL https://www.sf.net/home.view?siteLanguage=nl 的请求会将网站语言更改为荷兰语。以下示例显示了如何拦截语言环境：

You can enable changing of locales by adding the LocaleChangeInterceptor to one of the HandlerMapping definitions. It detects a parameter in the request and changes the locale accordingly, calling the setLocale method on the LocaleResolver in the dispatcher’s application context. The next example shows that calls to all *.view resources that contain a parameter named siteLanguage now changes the locale. So, for example, a request for the URL, https://www.sf.net/home.view?siteLanguage=nl, changes the site language to Dutch. The following example shows how to intercept the locale:

<bean id="localeChangeInterceptor"
		class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
	<property name="paramName" value="siteLanguage"/>
</bean>

<bean id="localeResolver"
		class="org.springframework.web.servlet.i18n.CookieLocaleResolver"/>

<bean id="urlMapping"
		class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
	<property name="interceptors">
		<list>
			<ref bean="localeChangeInterceptor"/>
		</list>
	</property>
	<property name="mappings">
		<value>/**/*.view=someController</value>
	</property>
</bean>