精通SpringBoot——第二篇：视图解析器，静态资源和区域配置

今天让我们来看看另一个重要的类：WebMvcAutoConfigurationAdapter。先来看看它的声明：

@Configuration @Import(EnableWebMvcConfiguration.class) @EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class }) @Order(0) public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer, ResourceLoaderAware { 

很显然，它也是SpringBoot的一个配置类，@Improt注解是被用来整合所有在@Configuration注解中定义的bean配置。这其实很像我们将多个XML配置文件导入到单个文件的情形。@Import注解实现了相同的功能。
再往下看可以看到SpringBoot中常见的viewResolver

 @Bean @ConditionalOnMissingBean public InternalResourceViewResolver defaultViewResolver() { InternalResourceViewResolver resolver = new InternalResourceViewResolver(); resolver.setPrefix(this.mvcProperties.getView().getPrefix()); resolver.setSuffix(this.mvcProperties.getView().getSuffix()); return resolver; } @Bean @ConditionalOnBean(View.class) @ConditionalOnMissingBean public BeanNameViewResolver beanNameViewResolver() { BeanNameViewResolver resolver = new BeanNameViewResolver(); resolver.setOrder(Ordered.LOWEST_PRECEDENCE - 10); return resolver; } @Bean @ConditionalOnBean(ViewResolver.class) @ConditionalOnMissingBean(name = "viewResolver", value = ContentNegotiatingViewResolver.class) public ContentNegotiatingViewResolver viewResolver(BeanFactory beanFactory) { ContentNegotiatingViewResolver resolver = new ContentNegotiatingViewResolver(); resolver.setContentNegotiationManager( beanFactory.getBean(ContentNegotiationManager.class)); // ContentNegotiatingViewResolver uses all the other view resolvers to locate // a view so it should have a high precedence resolver.setOrder(Ordered.HIGHEST_PRECEDENCE); return resolver; }

接着往下看，可以看到这个是配置区域的。@ConditionalOnProperty表示如果在application.properties中配置了spring.mvc.locale属性，则该配置会生效。

 @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; }

再往下看是配置静态资源（包括/webjars/**，classpath:/META-INF/resources/webjars/"）和favicon（可以通过在application.properties中设置spring.mvc.favicon.enabled来启用或禁用）

好了，文章到这里就结束了，静态资源这一块并没有什么特别的地方。我们需要理解的是这几个注解的用法，还有使用了配置属性，可以允许用户对其进行自定义。还有一个值得提一下，默认的地域解析器只会处理一个地域，通过上面提到的spring.mvc.locale来配置。