SpringBoot--国际化

2）、国际化

1）、编写国际化配置文件；**

2）、使用ResourceBundleMessageSource管理国际化资源文件

3）、在页面使用fmt:message取出国际化内容

步骤：

1）、编写国际化配置文件，抽取页面需要显示的国际化消息

2）、SpringBoot自动配置好了管理国际化资源文件的组件；

@ConfigurationProperties(prefix = "spring.messages")
public class MessageSourceAutoConfiguration {
    
    /**
	 * 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messages.properties；
    
    @Bean
	public MessageSource messageSource() {
		ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
		if (StringUtils.hasText(this.basename)) {
            //设置国际化资源文件的基础名（去掉语言国家代码的）
			messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray(
					StringUtils.trimAllWhitespace(this.basename)));
		}
		if (this.encoding != null) {
			messageSource.setDefaultEncoding(this.encoding.name());
		}
		messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale);
		messageSource.setCacheSeconds(this.cacheSeconds);
		messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat);
		return messageSource;
	}

3）、去页面获取国际化的值；

<!DOCTYPE html>
<html lang="en"  xmlns:th="http://www.thymeleaf.org">
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
		<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
		<meta name="description" content="">
		<meta name="author" content="">
		<title>Signin Template for Bootstrap</title>
		<!-- Bootstrap core CSS -->
		<link href="asserts/css/bootstrap.min.css" th:href="@{/webjars/bootstrap/4.0.0/css/bootstrap.css}" rel="stylesheet">
		<!-- Custom styles for this template -->
		<link href="asserts/css/signin.css" th:href="@{/asserts/css/signin.css}" rel="stylesheet">
	</head>

	<body class="text-center">
		<form class="form-signin" action="dashboard.html">
			<img class="mb-4" th:src="@{/asserts/img/bootstrap-solid.svg}" src="asserts/img/bootstrap-solid.svg" alt="" width="72" height="72">
			<h1 class="h3 mb-3 font-weight-normal" th:text="#{login.tip}">Please sign in</h1>
			<label class="sr-only" th:text="#{login.username}">Username</label>
			<input type="text" class="form-control" placeholder="Username" th:placeholder="#{login.username}" required="" autofocus="">
			<label class="sr-only" th:text="#{login.password}">Password</label>
			<input type="password" class="form-control" placeholder="Password" th:placeholder="#{login.password}" required="">
			<div class="checkbox mb-3">
				<label>
          		<input type="checkbox" value="remember-me"/> [[#{login.remember}]]
        </label>
			</div>
			<button class="btn btn-lg btn-primary btn-block" type="submit" th:text="#{login.btn}">Sign in</button>
			<p class="mt-5 mb-3 text-muted">© 2017-2018</p>
			<a class="btn btn-sm">中文</a>
			<a class="btn btn-sm">English</a>
		</form>

	</body>

</html>

效果：根据浏览器语言设置的信息切换了国际化；

原理：

​ 国际化Locale（区域信息对象）；LocaleResolver（获取区域信息对象）；

		@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;
		}
默认的就是根据请求头带来的区域信息获取Locale进行国际化

4）、点击链接切换国际化

/**
 * 可以在连接上携带区域信息
 */
public class MyLocaleResolver implements LocaleResolver {
    
    @Override
    public Locale resolveLocale(HttpServletRequest request) {
        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) {

    }
}


 @Bean
    public LocaleResolver localeResolver(){
        return new MyLocaleResolver();
    }
}

修改页面：

	<a class="btn btn-sm" th:href="@{/index.html(l='zh_CN')}">中文</a>
	<a class="btn btn-sm" th:href="@{/index.html(l='en_US')}">English</a>