本章开始将围绕实际项目来学习，之后涉及到的学习的资料可以在Bootstrap的示例中找到。
要完成其实很简单，主要按以下步骤：
- 编写国际化配置文件
- 使用ResourceBundleMessageSource管理国际化资源文件
- 在页面取出国际化内容
一.编写国际化配置文件
配置
在开始编写国际化配置文件之前，需要做一个准备工作：
选择File-Other Setting-Default Setting-File Encodings 按照上图配置，防止乱码出现
国际化配置文件
文件名命名规则基础名+语言国家代码+.properties，默认可以不加语言国家代码如xxx.properties, xxx_zh_CN.properties,xxx_en_US.properties,当IDEA检测到你的国际化配置，就会转成上图的国际化视图。
二.管理国际化资源文件
有关ResourceBundleMessageSource配置当然SpringBoot已经帮你完成了，我们查看他对应的自动配置类MessageSourceAutoConfiguration。
@Bean
public MessageSource messageSource() {
MessageSourceProperties properties = messageSourceProperties();
ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
if (StringUtils.hasText(properties.getBasename())) {
messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray(
StringUtils.trimAllWhitespace(properties.getBasename())));
}
if (properties.getEncoding() != null) {
messageSource.setDefaultEncoding(properties.getEncoding().name());
}
messageSource.setFallbackToSystemLocale(properties.isFallbackToSystemLocale());
Duration cacheDuration = properties.getCacheDuration();
if (cacheDuration != null) {
messageSource.setCacheMillis(cacheDuration.toMillis());
}
messageSource.setAlwaysUseMessageFormat(properties.isAlwaysUseMessageFormat());
messageSource.setUseCodeAsDefaultMessage(properties.isUseCodeAsDefaultMessage());
return messageSource;
}
public class MessageSourceProperties {
/**
* Comma-separated list of basenames (essentially a fully-qualified classpath
* location), each following the ResourceBundle convention with relaxed support for
* slash based locations. If it doesn't contain a package qualifier (such as
* "org.mypackage"), it will be resolved from the classpath root.
*/
private String basename = "messages";
//我们的配置文件可以直接放在类路径下叫message.properties，就不需要做任何配置就可以做国际化
/**
* Message bundles encoding.
*/
经过查看配置文件得知，假如我们需要使用的自己的国际化配置，需要在配置文件中写入包名
spring.messages.basename=inter.login
三.在页面取出国际化内容
我们继续查看Thymeleaf文档：
- Variable Expressions: ${...}
- Selection Variable Expressions: *{...}
- Message Expressions: #{...}
- Link URL Expressions: @{...}
- Fragment Expressions: ~{...}
也就是Message内容是通过#{...}语句取出的,完成后网页就可以随着浏览器语言环境的变化切换语言了,代码在文章结尾给出。
原理：
国际化Locale(区域信息对象) ；通过LocaleResolver（区域信息解析器）去操作，当然SpringBoot也自动配置了区域信息解析器，看一下代码：
@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
public LocaleResolver localeResolver() {
if (this.mvcProperties
.getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
return new FixedLocaleResolver(this.mvcProperties.getLocale());
}
AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
return localeResolver;
}
以上代码的逻辑：假如取到固定的WebMvcProperties.LocaleResolver.FIXED就使用固定的，否则就使用AcceptHeaderLocaleResolver，AcceptHeaderLocaleResolver作用是根据请求头获取区域信息。
请求头
当我们想在代码中加入语言切换的功能，那么就要添加自己的区域信息解析器。
定义自己的区域信息解析器：
/**
* @author BaoZhou
* @date 2018/5/15
*/
public class MyLocaleResolver implements LocaleResolver {
@Override
public Locale resolveLocale(HttpServletRequest request) {
//根据得到参数重新构造locale
String l = request.getParameter("l");
Locale locale = Locale.getDefault();
if(!StringUtils.isEmpty(l))
{
String[] split = l.split("_");
locale = new Locale(split[0],split[1]);
}
return locale;
}
@Override
public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
}
}
添加到容器中：
@Bean
public LocaleResolver localeResolver() {
return new MyLocaleResolver();
}
网页代码：
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->
<meta name="description" content="">
<meta name="author" content="">
<link rel="icon" th:href="@{assets/brand/favicon.ico}">
<title>Signin Template for Bootstrap</title>
<!-- Bootstrap core CSS -->
<link th:href="@{dist/css/bootstrap.min.css}" rel="stylesheet">
<!-- IE10 viewport hack for Surface/desktop Windows 8 bug -->
<link th:href="@{assets/css/ie10-viewport-bug-workaround.css}" rel="stylesheet">
<!-- Custom styles for this template -->
<link th:href="@{assets/css/signin.css}" rel="stylesheet">
<!-- Just for debugging purposes. Don't actually copy these 2 lines! -->
<!--[if lt IE 9]>
<script src="../assets/js/ie8-responsive-file-warning.js"></script><![endif]-->
<script th:src="@{assets/js/ie-emulation-modes-warning.js}"></script>
<!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->
</head>
<body class="text-center">
<div class="container">
<form class="form-signin">
<h2 class="form-signin-heading" th:text="#{login.tip}">Please sign in</h2>
<label for="inputEmail" class="sr-only" th:text="#{login.username}">Email address</label>
<input type="email" id="inputEmail" class="form-control" th:placeholder="#{login.username}" required autofocus>
<label for="inputPassword" class="sr-only" th:text="#{login.password}">Password</label>
<input type="password" id="inputPassword" class="form-control" th:placeholder="#{login.password}" required>
<div class="checkbox">
<label>
<input type="checkbox" value="remember-me" th:text="#{login.remember}">
</label>
</div>
<button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign in</button>
</form>
<p class="mt-5 mb-3 text-muted">@2018-2019</p>
<a btn class="btn btn-sm" th:href="@{/index(l='zh_CN')}">中文</a>
<a btn class="btn btn-sm" th:href="@{/index(l='en_US')}">English</a>
</div> <!-- /container -->
<!-- IE10 viewport hack for Surface/desktop Windows 8 bug -->
<script src="../assets/js/ie10-viewport-bug-workaround.js"></script>
</body>
</html>
运行结果
运行结果
大功告成，十分简单易懂。收工！
