SpringBoot静态资源映射揭秘

SpringBoot的Web开发

1.使用springboot进行web端的开发

（1）创建springboot应用，选择我们需要的模块

（2）在yml修改少量的配置就可以运行

（3）编写业务代码

XxxAutoConfiguration：帮我们给容器中自动配置组件；

XxxProperties：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

（1）ResourceProperties类

WebMvcAuotConfiguration：

java 复制代码

@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();
//静态资源文件夹映射
if (!registry.hasMappingForPattern(staticPathPattern)) {

    customizeResourceHandlerRegistration(registry.addResourceHandler(staticPathPattern).addResourceLocations(this.resourceProperties.getStaticLocations()).setCachePeriod(cachePeriod));

}
} /
/配置欢迎页映射
@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(
       ResourceProperties resourceProperties) {
       return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),

this.mvcProperties.getStaticPathPattern());
}
//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;
 }
}

ResourceProperties是一个springboot自带的有关配置映射的类，有默认的映射路径，如果想要修改的话可以继承+重写他的方法来自定义路径

（2）默认路径

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；

WebJars - Web Libraries in Jars

localhost:8085/webjars/jquery/3.3.1/jquery.js

引入jquery-webjar

XML 复制代码

<!‐‐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>

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赵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