springBoot快速访问工程目录下的静态资源

By default, resources are mapped on /**, but you can tune that with the spring.mvc.static-path-pattern property. For instance, relocating all resources to /resources/** can be achieved as follows:

PropertiesYaml
spring.mvc.static-path-pattern=/resources/**

spring.mvc.static-path-pattern=/res/**

/spring-boot-autoconfigure-2.5.1.jar!/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.class

@Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            // 相当于一个开关去控制静态资源处理器的加载，默认为true，设置为false就会禁止所有规则
            if (!this.resourceProperties.isAddMappings()) {
                logger.debug("Default resource handling disabled");
                return;
            }
            //第一个就配置webjars的访问规则，规定在类路径的/META-INF/resources/webjars/路径下，感兴趣的同学可以点进方法去，里面还配置了webjars的浏览器端缓存时间，是在application。propertities中的一个配置项 spring.web.resources.cache.period  
            addResourceHandler(registry, "/webjars/**", "classpath:/META-INF/resources/webjars/");
            //这里配置了静态资源的四个访问路径
            addResourceHandler(registry, this.mvcProperties.getStaticPathPattern(), (registration) -> {
                registration.addResourceLocations(this.resourceProperties.getStaticLocations());
                if (this.servletContext != null) {
                    ServletContextResource resource = new ServletContextResource(this.servletContext, SERVLET_LOCATION);
                    registration.addResourceLocations(resource);
                }
            });
        }

#springapplication.propertities中配置
spring.web.resources.add-mappings=false

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

WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders,
            ApplicationContext applicationContext, Resource welcomePage, String staticPathPattern) {
        if (welcomePage != null && "/**".equals(staticPathPattern)) {
            logger.info("Adding welcome page: " + welcomePage);
            setRootViewName("forward:index.html");
        }
        else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
            logger.info("Adding welcome page template: index");
            setRootViewName("index");
        }
    }