在按照之前的那个文章升级使用Thymeleaf3后，使用MessageSouce的国际化会出现找不到的情况。到处找文章研究了很久还是自己找到了解决办法。
解决办法是HTML模板用application.yml里面配置，CSS和JS模板在代码里面创建。

speing:
  thymeleaf:
    cache: false
    mode: HTML
    view-names:
      - '*.html'
    suffix: ~
  messages:
    basename: i18n/messages
    cache-seconds: 0

@Configuration
public class ThymeleafConfig implements ApplicationContextAware {
    private static final String UTF8 = "UTF-8";
    private ApplicationContext applicationContext;

    private String[] array(String ...args) {
        return args;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    private TemplateEngine templateEngine(ITemplateResolver templateResolver) {
        SpringTemplateEngine engine = new SpringTemplateEngine();
        engine.setTemplateResolver(templateResolver);
        return engine;
    }

    private ITemplateResolver cssTemplateResolver() {
        SpringResourceTemplateResolver resolver = new SpringResourceTemplateResolver();
        resolver.setApplicationContext(applicationContext);
        resolver.setPrefix("classpath:/static/css/");
        resolver.setTemplateMode(TemplateMode.CSS);
        resolver.setCacheable(false);
        return resolver;
    }

    @Bean
    public ViewResolver cssViewResolver() {
        ThymeleafViewResolver resolver = new ThymeleafViewResolver();
        resolver.setTemplateEngine(templateEngine(cssTemplateResolver()));
        resolver.setContentType("text/css");
        resolver.setCharacterEncoding(UTF8);
        resolver.setViewNames(array("*.css"));
        resolver.setCache(false);
        return resolver;
    }

    private ITemplateResolver javascriptTemplateResolver() {
        SpringResourceTemplateResolver resolver = new SpringResourceTemplateResolver();
        resolver.setApplicationContext(applicationContext);
        resolver.setPrefix("classpath:/static/js/");
        resolver.setTemplateMode(TemplateMode.JAVASCRIPT);
        resolver.setCacheable(false);
        return resolver;
    }

    @Bean
    public ViewResolver javascriptViewResolver() {
        ThymeleafViewResolver resolver = new ThymeleafViewResolver();
        resolver.setTemplateEngine(templateEngine(javascriptTemplateResolver()));
        resolver.setContentType("application/javascript");
        resolver.setCharacterEncoding(UTF8);
        resolver.setViewNames(array("*.js"));
        resolver.setCache(false);
        return resolver;
    }

}