1、静态资源访问

1.1、静态资源目录

当前项目类路径下：called /static(or /public or /resourcesor /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，不能处理的请求则会交给静态资源处理器，静态资源能找到则访问，如果找不到则为404

2、静态资源访问前缀

默认无前缀，如果要自定义的话在application.yml中做以下操作：

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

访问则会成为：当前项目+static-path-pattern+静态资源名=静态资源文件夹下找2.3、webjar

2.3、webjar

自动映射： https://www.webjars.org/

                <dependency>
            <groupId>org.webjars</groupId>
            <artifactId>jquery</artifactId>
            <version>3.5.1</version>
        </dependency>

引入pom链接，默认访问路径/webjars/**，下面是一个访问的例子：
访问地址： http://localhost:8080/webjars/jquery/3.5.1/jquery.js webjars/后面的地址要按照依赖中的包路径来

2.4、欢迎页支持的几种方式

静态资源路径下 index.html

可以配置静态资源路径

但是不能配置静态资源访问前缀，否则将导致index.html不能被默认访问

spring:
#mvc:
#static-path-pattern: /res/** #改变静态资源前缀路径
#static-path-pattern: /**  默认
web:
resources:
 static-locations: [classpath:/haha/] #改变静态资源默认文件夹位置

controller能处理/index

2.5、自定义Favicon网页标签图标

#spring:
#  mvc:
#    static-path-pattern: /res/** #改变静态资源前缀路径，这个会导致welcome page功能失效
#  #static-path-pattern: /**  默认
#  web:
#    resources:
#      static-locations: [classpath:/haha/] #改变静态资源默认文件夹位置

在/resouces/static目录下放入favicon.ico图片文件

2.6、静态资源配置原理

SpringBoot启动默认加载xxxAutoConfiguration类（自动配置）
所有的自动配置在org.Springframework.boot:spring-boot-autoconfigure下的文件中

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) //如果容器中有指定类型的组件则下面的所有的配置都不生效
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class,
      ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {}

给容器中配了什么？

@SuppressWarnings("deprecation")
  @Configuration(proxyBeanMethods = false)
  @Import(EnableWebMvcConfiguration.class)
  @EnableConfigurationProperties({ WebMvcProperties.class,
          org.springframework.boot.autoconfigure.web.ResourceProperties.class, WebProperties.class })
  @Order(0)
  public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer {}

配置文件的相关属性和xxx进行了绑定，WebMvcProperties==spring.mvc、ResourceProperties==spring.resources

一个配置类中只有一个有参构造

//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绑定所有值的对象
//WebProperties mvcProperties 获取和spring.mvc绑定的所有值的对象
//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  **重点
//DispatcherServletPath
//ServletRegistrationBean 给应用注册Servlet、Filter...
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();
      }

资源处理默认规则

@Override
protected void addResourceHandlers(ResourceHandlerRegistry registry) {
  super.addResourceHandlers(registry);
  if (!this.resourceProperties.isAddMappings()) {
      logger.debug("Default resource handling disabled");
      return;
  }
  ServletContext servletContext = getServletContext();
  addResourceHandler(registry, "/webjars/**", "classpath:/META-INF/resources/webjars/");
  addResourceHandler(registry, this.mvcProperties.getStaticPathPattern(), (registration) -> {
      registration.addResourceLocations(this.resourceProperties.getStaticLocations());
      if (servletContext != null) {
          registration.addResourceLocations(new ServletContextResource(servletContext, SERVLET_LOCATION));
      }
  });
}

spring:
web:
  resources:
    add-mappings: false #禁用静态资源规则
    cache:
      period: 11000 #以秒为单位
#  mvc:
#    static-path-pattern: /res/** #改变静态资源前缀路径

静态资源默认的四个位置

public static class Resources {
      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;
}

欢迎页的默认配置 ```java //说明：HandlerMapping是处理器映射，其中保存了每一个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;

}

//这里已经将欢迎页写死（”/“.equals），所以我们在配置文件中修改没有用 WelcomePageHandlerMapping(TemplateAvailabilityProviders templateAvailabilityProviders, ApplicationContext applicationContext, Resource welcomePage, String staticPathPattern) { if (welcomePage != null && “/“.equals(staticPathPattern)) { //要使用欢迎页功能，必须是/** logger.info(“Adding welcome page: “ + welcomePage); setRootViewName(“forward:index.html”); } else if (welcomeTemplateExists(templateAvailabilityProviders, applicationContext)) { //调用Controller /index logger.info(“Adding welcome page template: index”); setRootViewName(“index”); } } ```

SpringBoot2

web场景-静态资源规则与定制化