2018-8-29对于SpringBoot的静态资源的映射规则学习

springboot, 学习笔记

SpringBoot对静态资源的映射规则

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@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));
	}
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@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties {

	private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
			"classpath:/META-INF/resources/", "classpath:/resources/",
			"classpath:/static/", "classpath:/public/" };

	/**
	 * Locations of static resources. Defaults to classpath:[/META-INF/resources/,
	 * /resources/, /static/, /public/].
	 */
	private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS;

	/**

使用webjars

所有/webjars/**; 都去classpath:META-INF/resources/webjars/找资源
webjars:以jar包的形式引入静态资源 https://www.webjars.org/
例如:

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<!--导入webjars中的bootstraps依赖-->
    <dependency>
        <groupId>org.webjars</groupId>
        <artifactId>bootstrap</artifactId>
        <version>4.1.3</version>
    </dependency>

目录结构如下:

可以看到由于导入了maven依赖在maven扩展中已经导入了相应的包根据规则找到了bootstrap类路径和他的META-INF从而找了该静态文件的引用

使用自定义的模块

使用/**访问当前项目的任何资源
>> classpath:/META-INF/resources/
>> classpath: /resources/
>> classpath: /static/
>> classpath: /public/
>> / 当前项目的根路径

欢迎页

静态资源文件夹下的所有index.html页面 都会被/** 映射

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 */
final class WelcomePageHandlerMapping extends AbstractUrlHandlerMapping {

	private static final Log logger = LogFactory.getLog(WelcomePageHandlerMapping.class);

	private static final List<MediaType> MEDIA_TYPES_ALL = Collections
			.singletonList(MediaType.ALL);

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

所有的**/favicon.ico 都是在静态资源文件下找到的

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@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);

所起到的作用就是更改页面的ico 默认能在所有的静态资源文件夹的路径里扫描添加