SpringBoot之静态资源规则与定制化

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

@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;
    ...
}

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

<dependency>
    <groupId>org.webjars</groupId>
    <artifactId>jquery</artifactId>
    <version>3.6.4</version>
</dependency>

@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();
      //webjars的规则
            if (!registry.hasMappingForPattern("/webjars/**")) {
        customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**")
            .addResourceLocations("classpath:/META-INF/resources/webjars/")
            .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
      }
            //
      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

spring:
#  mvc:
#    static-path-pattern: /res/**   这个会导致welcome page功能失效
  resources:
    static-locations: [classpath:/haha/]

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的构造方法如下：
  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/**路径
      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");
    }
  }

spring:
#  mvc:
#    static-path-pattern: /res/**   这个会导致 Favicon 功能失效

@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 {
    ...
}

有参构造器所有参数的值都会从容器中确定
public WebMvcAutoConfigurationAdapter(WebProperties webProperties, WebMvcProperties mvcProperties,
    ListableBeanFactory beanFactory, ObjectProvider<HttpMessageConverters> messageConvertersProvider,
    ObjectProvider<ResourceHandlerRegistrationCustomizer> resourceHandlerRegistrationCustomizerProvider,
    ObjectProvider<DispatcherServletPath> dispatcherServletPath,
    ObjectProvider<ServletRegistrationBean<?>> servletRegistrations) {
  this.mvcProperties = mvcProperties;
  this.beanFactory = beanFactory;
  this.messageConvertersProvider = messageConvertersProvider;
  this.resourceHandlerRegistrationCustomizer = resourceHandlerRegistrationCustomizerProvider.getIfAvailable();
  this.dispatcherServletPath = dispatcherServletPath;
  this.servletRegistrations = servletRegistrations;
  this.mvcProperties.checkConfiguration();
}