SpringBoot2核心技术与响应式编程- web开发-静态资源配置原理

https://www.yuque.com/atguigu/springboot/vgzmgh

1.静态资源访问

只要静态资源放在类路径下: called /static (or /public or /resources or /META-INF/resources

访问 : 当前项目根路径/ + 静态资源名

原理: 静态映射/**。

请求进来,先去找Controller看能不能处理。不能处理的所有请求又都交给静态资源处理器。静态资源也找不到则响应404页面

改变默认的静态资源路径(静态资源放在指定目录下)

spring:
  resources:
    static-locations: [classpath:/haha/]

  

静态资源访问前缀
spring:
  mvc:
    static-path-pattern: /res/**

当前项目 + static-path-pattern + 静态资源名 = 静态资源文件夹下找

2.欢迎页

  • 静态资源路径下 index.html        (但是不可以配置静态资源的访问前缀。否则导致 index.html不能被默认访问)
  • spring:
    #  mvc:
    #    static-path-pattern: /res/**   这个会导致welcome page功能失效  新版springmvc已经解决了这个bug
    
      resources:
        static-locations: [classpath:/haha/]
  • controller能处理/index

3.自定义 Favicon

favicon.ico 放在静态资源目录下即可。(不能配置静态资源访问前缀)

静态资源配置原理:

SpringBoot启动默认加载 xxxAutoConfiguration 类(自动配置类)

SpringMVC功能的自动配置类 WebMvcAutoConfiguration,生效

 

@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication(type = Type.SERVLET)
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class })
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class,
		ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {}

  

	@Configuration(proxyBeanMethods = false)
	@Import(EnableWebMvcConfiguration.class)
	@EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class })
	@Order(0)
	public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer {}
@EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.class })
配置文件的相关属性和xxx进行了绑定。WebMvcProperties==spring.mvc、ResourceProperties==spring.resources

配置类只有一个有参构造器
	//有参构造器所有参数的值都会从容器中确定
//ResourceProperties resourceProperties;获取和spring.resources绑定的所有的值的对象
//WebMvcProperties mvcProperties 获取和spring.mvc绑定的所有的值的对象
//ListableBeanFactory beanFactory Spring的beanFactory
//HttpMessageConverters 找到所有的HttpMessageConverters
//ResourceHandlerRegistrationCustomizer 找到 资源处理器的自定义器。=========
//DispatcherServletPath  
//ServletRegistrationBean   给应用注册Servlet、Filter....
	public WebMvcAutoConfigurationAdapter(ResourceProperties resourceProperties, WebMvcProperties mvcProperties,
				ListableBeanFactory beanFactory, ObjectProvider<HttpMessageConverters> messageConvertersProvider,
				ObjectProvider<ResourceHandlerRegistrationCustomizer> resourceHandlerRegistrationCustomizerProvider,
				ObjectProvider<DispatcherServletPath> dispatcherServletPath,
				ObjectProvider<ServletRegistrationBean<?>> servletRegistrations) {
			this.resourceProperties = resourceProperties;
			this.mvcProperties = mvcProperties;
			this.beanFactory = beanFactory;
			this.messageConvertersProvider = messageConvertersProvider;
			this.resourceHandlerRegistrationCustomizer = resourceHandlerRegistrationCustomizerProvider.getIfAvailable();
			this.dispatcherServletPath = dispatcherServletPath;
			this.servletRegistrations = servletRegistrations;
		}

 

资源处理的默认规则
@Override
		public void addResourceHandlers(ResourceHandlerRegistry registry) {
			if (!this.resourceProperties.isAddMappings()) {
				logger.debug("Default resource handling disabled");
				return;
			}
//可以配置缓存 Duration cachePeriod = this.resourceProperties.getCache().getPeriod(); CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl(); //webjars的规则 if (!registry.hasMappingForPattern("/webjars/**")) { customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**") .addResourceLocations("classpath:/META-INF/resources/webjars/") .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl)); } //静态资源路径 String staticPathPattern = this.mvcProperties.getStaticPathPattern(); if (!registry.hasMappingForPattern(staticPathPattern)) { customizeResourceHandlerRegistration(registry.addResourceHandler(staticPathPattern) .addResourceLocations(getResourceLocations(this.resourceProperties.getStaticLocations())) .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl)); } }

  

spring:
#  mvc:
#    static-path-pattern: /res/**

  resources:
    add-mappings: false   禁用所有静态资源规则

 静态资源默认路径

@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;

  欢迎页的处理规则

	HandlerMapping:处理器映射。保存了每一个Handler能处理哪些请求。	

	@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, Optional<Resource> welcomePage, String staticPathPattern) {
		if (welcomePage.isPresent() && "/**".equals(staticPathPattern)) {
            //要用欢迎页功能,必须是/**
			logger.info("Adding welcome page: " + welcomePage.get());
			setRootViewName("forward:index.html");
		}
		else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) {
            // 调用Controller  /index
			logger.info("Adding welcome page template: index");
			setRootViewName("index");
		}
	}

  



原文地址:https://www.cnblogs.com/yxj808/p/15304093.html