SpringBoot对静态资源的映射规则详解解读

<!‐‐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>3.4.1</version>
</dependency>

    @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));
            }
        }

    @Bean
        public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext) {
            WelcomePageHandlerMapping welcomePageHandlerMapping = new WelcomePageHandlerMapping(
                    new TemplateAvailabilityProviders(applicationContext), applicationContext, getWelcomePage(),
                    this.mvcProperties.getStaticPathPattern());
            welcomePageHandlerMapping.setInterceptors(getInterceptors());
            return welcomePageHandlerMapping;
        }

@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;
            }
　　　　　　　//  映射**/favicon.ico
            @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);
            }
        }
    }