【 SpringBoot Web开发 】—— 对 静态资源 的映射规则

SpringBoot Web 开发简介

使用 SpringBoot

• 创建 SpringBoot 应用，选中我们需要的模块
  

• SpringBoot 已经默认将这些场景配置好了，只需要在配置文件中指定少量配置就可以运行起来
  
  

• 自己编写业务代码

SpringBoot 对 静态资源 的映射规则

@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties {
    // 可以设置和静态资源有关的参数，缓存时间等

Web 的自动配置都在 类 WebMvcAutoConfiguration 下面：

		@Override
		public void addResourceHandlers(ResourceHandlerRegistry registry) {
			if (!this.resourceProperties.isAddMappings()) {
				logger.debug("Default resource handling disabled");
				return;
			}
			Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
			CacheControl cacheControl = this.resourceProperties.getCache()
					.getCachecontrol().toHttpCacheControl();
			if (!registry.hasMappingForPattern("/webjars/**")) {
				customizeResourceHandlerRegistration(registry
						.addResourceHandler("/webjars/**")
						.addResourceLocations("classpath:/META-INF/resources/webjars/")
						.setCachePeriod(getSeconds(cachePeriod))
						.setCacheControl(cacheControl));
			}
			String staticPathPattern = this.mvcProperties.getStaticPathPattern();
			// 静态资源文件夹映射
			if (!registry.hasMappingForPattern(staticPathPattern)) {
				customizeResourceHandlerRegistration(
						registry.addResourceHandler(staticPathPattern)
								.addResourceLocations(getResourceLocations(
										this.resourceProperties.getStaticLocations()))
								.setCachePeriod(getSeconds(cachePeriod))
								.setCacheControl(cacheControl));
			}
		}

        // 配置欢迎页映射
		@Bean
		public WelcomePageHandlerMapping welcomePageHandlerMapping(
				ApplicationContext applicationContext) {
			return new WelcomePageHandlerMapping(
					new TemplateAvailabilityProviders(applicationContext),
					applicationContext, getWelcomePage(),
					this.mvcProperties.getStaticPathPattern());
		}

        // 配置喜欢的图标 
		@Configuration
		@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
		public static class FaviconConfiguration implements ResourceLoaderAware {

			private final ResourceProperties resourceProperties;

			private ResourceLoader resourceLoader;

			public FaviconConfiguration(ResourceProperties resourceProperties) {
				this.resourceProperties = resourceProperties;
			}

			@Override
			public void setResourceLoader(ResourceLoader resourceLoader) {
				this.resourceLoader = resourceLoader;
			}

			@Bean
			public SimpleUrlHandlerMapping faviconHandlerMapping() {
				SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
				mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
				mapping.setUrlMap(Collections.singletonMap("**/favicon.ico",
						faviconRequestHandler()));
				return mapping;
			}

			@Bean
			public ResourceHttpRequestHandler faviconRequestHandler() {
				ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
				requestHandler.setLocations(resolveFaviconLocations());
				return requestHandler;
			}

			private List<Resource> resolveFaviconLocations() {
				String[] staticLocations = getResourceLocations(
						this.resourceProperties.getStaticLocations());
				List<Resource> locations = new ArrayList<>(staticLocations.length + 1);
				Arrays.stream(staticLocations).map(this.resourceLoader::getResource)
						.forEach(locations::add);
				locations.add(new ClassPathResource("/"));
				return Collections.unmodifiableList(locations);
			}

		}

1、所有 /webjars/** 请求 ，都去 classpath:/META-INF/resources/webjars/ 找资源

webjars：以 jar 包的方式引入静态资源

参考 https://www.webjars.org/

pom导入依赖：

		<!-- 引入jquery-webjar，在访问的时候只需要写 webjars下面资源的名称即可 -->
		<dependency>
			<groupId>org.webjars</groupId>
			<artifactId>jquery</artifactId>
			<version>3.3.1</version>
		</dependency>

例如：想要访问上面的 jquery.js ，启动启动项，浏览器输入 http://localhost:8080/webjars/jquery/3.3.1/jquery.js

2、"/**" 访问当前项目的任何资源，都去（静态资源的文件夹）找映射

"classpath:/META‐INF/resources/"
"classpath:/resources/"
"classpath:/static/"
"classpath:/public/"
"/"：当前项目的根路径

例如：localhost:8080/abc，去静态资源文件夹里面找 abc

3、欢迎页； 静态资源文件夹下的所有 index.html 页面；被 “/**” 映射

localhost:8080/，找index页面

4、所有的 **/favicon.ico 都是在静态资源文件下找

配置喜欢的图标 ，直接放到静态资源目录下即可。