SpringMVC--国际化的三种方式详解（AcceptLanguageLocaleResolver、SessionLocaleResovler、CookieLocaleResolver）

国际化概述

基于浏览器请求的国际化实现

新建实体类

package pers.zhang.entity;/*** @author zhang* @date 2019/11/28 - 11:34*/
public class User {private String loginName;private String password;private int age;private String email;private String phone;public String getLoginName() {return loginName;}public void setLoginName(String loginName) {this.loginName = loginName;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone;}@Overridepublic String toString() {return "User{" +"loginName='" + loginName + '\'' +", password='" + password + '\'' +", age=" + age +", email='" + email + '\'' +", phone='" + phone + '\'' +'}';}
}

在src根路径下，新建两个资源文件：
message_en_US.properties

loginName=LoginName
password=Password
age=Age
email=Email
phone=Phone
submit=Submit
welcome=Welcome {0}, Congratulations on your registration.
title=Register Page
userName=Administrator
info=Your registration information is as follows

message_zh_CH.properties

loginName=\u540D\u79F0
password=\u5BC6\u7801
age=\u5E74\u9F84
email=\u90AE\u7BB1
phone=\u7535\u8BDD
submit=\u6CE8\u518C
welcome=\u6B22\u8FCE {0},\u606D\u559C\u60A8\u6CE8\u518C\u6210\u529F
title=\u6CE8\u518C\u9875\u9762
userName=\u7BA1\u7406\u5458
info=\u60A8\u7684\u6CE8\u518C\u4FE1\u606F\u5982\u4E0B

在springmvc.xml中加载国际化资源文件：

 <bean name="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"><!-- 国际化资源文件名 --><property name="basename" value="message"/></bean><!-- AcceptHeaderLocaleResolver 因为是默认语言区域解析，可以不配置 --><bean name="localeResolver" class="org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver"/>

在webapp下的jsp文件夹中新建registerForm.jsp和success.jsp
registerForm.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8" isELIgnored="false" %>
<%@ taglib prefix="fm" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title><spring:message code="title"/></title>
</head>
<body><a href="registerForm?request_locale=zh_CN">中文</a> &nbsp; | &nbsp;<a href="registerForm?request_locale=en_US">英文</a><h3><spring:message code="title"/></h3><fm:form modelAttribute="user" action="register" method="post"><spring:message code="loginName"/>：<fm:input path="loginName"/><br><spring:message code="password"/>：<fm:input path="password"/><br><spring:message code="age"/>：<fm:input path="age"/><br><spring:message code="email"/>：<fm:input path="email"/><br><spring:message code="phone"/>：<fm:input path="phone"/><br><input type="submit" value="<spring:message code="submit"/>"><br></fm:form></body>
</html>

success.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8" isELIgnored="false" %>
<%@ taglib prefix="fm" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
</head>
<body><font color="blue"><h4><spring:message code="welcome" arguments="${requestScope.user.loginName }"/> </h4></font><spring:message code="info"/><br><spring:message code="password"/>：${user.password }<br><spring:message code="age"/>：${requestScope.user.age }<br><spring:message code="email"/>：${requestScope.user.email }<br><spring:message code="phone"/>：${requestScope.user.phone }<br></body>
</html>

在controller包中新建UserController

package pers.zhang.controller;import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.support.RequestContext;
import pers.zhang.entity.User;import javax.servlet.http.HttpServletRequest;/*** @author zhang* @date 2019/11/28 - 11:48*/
@Controller
public class UserController {@RequestMapping("/{formName}")public String registerForm(@PathVariable String formName, Model model){User user = new User();model.addAttribute("user", user);return formName;//动态跳转到页面}@RequestMapping(value = "/register", method = RequestMethod.POST)public String register(@ModelAttribute User user, Model model, HttpServletRequest request){//从后台代码获取国际化资源文件中的信息 userNameRequestContext requestContext = new RequestContext(request);String userName = requestContext.getMessage("userName");model.addAttribute("user", user);System.out.println(userName);return "success";}
}

测试：
修改浏览器的默认语言设置，并刷新页面，填入数据并提交：

基于HttpSession的国际化实现

基于HttpSession的国际化实现使用的是LocaleResolver接口的SessionLocaleResovler实现类，SessionLocaleResovler不是默认的语言区域解析器，需要对其进行显示配置。如果使用它，SpringMVC会从HttpSession作用域中获取用户所设置的语言区域，来确定使用哪个语言区域。通过请求参数改变国际化的值时，可使用Spring提供的国际化拦截器LocaleChangeInterceptor。

SessionLocaleResovler工作原理如下图：

修改springmvc.xml配置
注释默认的AcceptLanguageLocaleResolver

bean name="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"><!-- 国际化资源文件名 --><property name="basename" value="message"/></bean>
<!--    &lt;!&ndash; AcceptHeaderLocaleResolver 因为是默认语言区域解析，可以不配置 &ndash;&gt;-->
<!--    <bean name="localeResolver" class="org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver"/>--><!-- SessionLocaleResolver 配置 --><bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver"/><mvc:interceptors><!-- 如果采用了基于Session/Cookie的国际化，必须配置国际化操作拦截器 --><bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/></mvc:interceptors>

修改获取跳转页面的registerForm()方法

@RequestMapping(value = "/{formName}")public String registerForm(@PathVariable String formName, String request_locale,Model model, HttpServletRequest request){System.out.println("request_locale=" + request_locale);if(request_locale != null){if(request_locale.equals("zh_CN")){//设置中文环境Locale locale = new Locale("zh", "CN");request.getSession().setAttribute(SessionLocaleResolver.LOCALE_SESSION_ATTRIBUTE_NAME, locale);}else if(request_locale.equals("en_US")){//设置英文环境Locale locale = new Locale("en", "US");request.getSession().setAttribute(SessionLocaleResolver.LOCALE_SESSION_ATTRIBUTE_NAME, locale);}else{//使用之前的语言环境request.getSession().setAttribute(SessionLocaleResolver.LOCALE_SESSION_ATTRIBUTE_NAME, LocaleContextHolder.getLocale());}}User user = new User();model.addAttribute("user", user);return formName;//动态跳转页面}

测试
点击超链接切换语言：

基于Cookie的国际化实现

基于Cookie的国际化实现使用的是LocaleResolver接口CookieLocaleResolver 实现类，CookieLocaleResolver不是默认的语言区域解析器，需要对其进行显示配置。

修改springmvc.xml配置

    <bean name="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"><!-- 国际化资源文件名 --><property name="basename" value="message"/></bean>
<!--    &lt;!&ndash; AcceptHeaderLocaleResolver 因为是默认语言区域解析，可以不配置 &ndash;&gt;-->
<!--    <bean name="localeResolver" class="org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver"/>--><!-- SessionLocaleResolver 配置 -->
<!--    <bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver"/>--><!-- CookieLocaleResolver 配置--><bean id="localeResolver" class="org.springframework.web.servlet.i18n.CookieLocaleResolver"/><mvc:interceptors><!-- 如果采用了基于Session/Cookie的国际化，必须配置国际化操作拦截器 --><bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/></mvc:interceptors>

修改获取跳转页面的registerForm()方法

@RequestMapping(value = "/{formName}")public String registerForm(@PathVariable String formName, String request_locale, Model model,HttpServletRequest request, HttpServletResponse response){System.out.println("request_locale=" + request_locale);if(request_locale != null){if(request_locale.equals("zh_CN")){//设置中文环境Locale locale = new Locale("zh", "CN");(new CookieLocaleResolver()).setLocale(request,response,locale);}else if(request_locale.equals("en_US")){//设置英文环境Locale locale = new Locale("en", "US");(new CookieLocaleResolver()).setLocale(request,response,locale);}else{//使用之前的环境(new CookieLocaleResolver()).setLocale(request,response,LocaleContextHolder.getLocale());}}User user = new User();model.addAttribute("user", user);return formName;}

测试：点击标签切换语言环境
在浏览器调试窗口可以看到Cookie中的语言环境参数：