Spring Boot 靜態資源映射篇

Web開發

1.簡介:

使用Spring Boot :

創建Spring Boot應用選中我們需要的模塊; Spring Boot
已經默認將這些場景配置好了,只需要在配置文件中指定少量配置就可以運行起來;
自己可以編寫業務代碼;

自動配置原理:
這個場景Spring Boot 幫我們配置了什麼?

xxxAautoConfiguration:幫我們給容器中自動配置組件;
xxxProperties:配置類來瘋轉配置文件的內容;

2.Spring Boot 對靜態資源的映射規則

@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties implements ResourceLoaderAware {
  //可以設置和靜態資源有關的參數，緩存時間等

WebMvcAuotConfiguration：
		@Override
		public void addResourceHandlers(ResourceHandlerRegistry registry) {
			if (!this.resourceProperties.isAddMappings()) {
				logger.debug("Default resource handling disabled");
				return;
			}
			Integer cachePeriod = this.resourceProperties.getCachePeriod();
			if (!registry.hasMappingForPattern("/webjars/**")) {
				customizeResourceHandlerRegistration(
						registry.addResourceHandler("/webjars/**")
								.addResourceLocations(
										"classpath:/META-INF/resources/webjars/")
						.setCachePeriod(cachePeriod));
			}
			String staticPathPattern = this.mvcProperties.getStaticPathPattern();
          	//靜態資源文件夾映射
			if (!registry.hasMappingForPattern(staticPathPattern)) {
				customizeResourceHandlerRegistration(
						registry.addResourceHandler(staticPathPattern)
								.addResourceLocations(
										this.resourceProperties.getStaticLocations())
						.setCachePeriod(cachePeriod));
			}
		}

        //配置歡迎頁映射
		@Bean
		public WelcomePageHandlerMapping welcomePageHandlerMapping(
				ResourceProperties resourceProperties) {
			return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),
					this.mvcProperties.getStaticPathPattern());
		}

       //配置喜歡的圖標
		@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/ 找資源；

​ webjars：以jar包的方式引入靜態資源；
WEBjars

localhost:8080/webjars/jquery/3.3.1/jquery.js

<!--引入jquery-webjar-->在訪問的時候只需要寫webjars下面資源的名稱即可
		<dependency>
			<groupId>org.webjars</groupId>
			<artifactId>jquery</artifactId>
			<version>3.3.1</version>
		</dependency>

2）、"/**" 訪問當前項目的任何資源，都去（靜態資源的文件夾）找映射

"classpath:/META-INF/resources/", 
"classpath:/resources/",
"classpath:/static/", 
"classpath:/public/" 
"/"：當前項目的根路徑

localhost:8080/abc === 去靜態資源文件夾裏面找abc

3）、歡迎頁； 靜態資源文件夾下的所有index.html頁面；被"/**"映射；

​ localhost:8080/ 找index頁面

4）、所有的 **/favicon.ico 都是在靜態資源文件下找；