web开发 静态资源

1，简介

使用SpringBoot：

1）创建SpringBoot应用，选中需要的模块

2）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

3）自己编写业务代码

自动配置原理

xxxxAutoConfiguration：帮我们给容器中自动配置组件；
xxxxProperties:配置类来封装配置文件的内容；

2，SpringBoot对静态资源的映射规则

       //WebMvcAutoConfiguration
       public void addResourceHandlers(ResourceHandlerRegistry registry) {
            if (!this.resourceProperties.isAddMappings()) {
                logger.debug("Default resource handling disabled");
            } else {
                Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
                CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
                if (!registry.hasMappingForPattern("/webjars/**")) {
                    this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{"/webjars/**"}).addResourceLocations(new String[]{"classpath:/META-INF/resources/webjars/"}).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl).setUseLastModified(this.resourceProperties.getCache().isUseLastModified()));
                }

                String staticPathPattern = this.mvcProperties.getStaticPathPattern();
                //静态资源文件夹映射
                if (!registry.hasMappingForPattern(staticPathPattern)) {
                    this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{staticPathPattern}).addResourceLocations(WebMvcAutoConfiguration.getResourceLocations(this.resourceProperties.getStaticLocations())).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl).setUseLastModified(this.resourceProperties.getCache().isUseLastModified()));
                }

            }
        }

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

//配置喜欢的图标
@Configuration
@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
public static class FaviconConfiguration {
         private final ResourceProperties resourceProperties;
         public FaviconConfiguration(ResourceProperties resourceProperties) {
              this.resourceProperties = resourceProperties;
          }

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

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

webjars：以jar包的方式引入静态资源。

http://www.webjars.org

引入静态资源webjar的依赖

<!‐‐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>

 通过http://localhost:8080/webjars/jquery/3.3.1/jquery.js 访问

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

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.html页面

4）所有的**/favicon.ico都是在静态资源文件下找