静态资源映射规则
1.静态资源访问
1.0 查看官网文档对应说明
1.1 静态资源目录
- " /** " 访问当前项目的任何资源 (静态资源的文件夹)
- 默认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
静态资源访问路径优先级：
META-INF/resources
resources
static
public
1.2 静态资源访问前缀
默认无前缀
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
为了让拦截时能区分出静态资源和动态资源，所以规定静态资源前面加个前缀，拦截器在看到指定前缀时就放行，从而达到动态静态分开的目的。
请注意: 加了静态资源访问前缀后，访问静态资源时，就必须加上前缀，这个多用于拦截器对静态资源的拦截
1.3 改变默认的静态资源路径----自己规定静态资源都放到哪个路径下面
spring:
mvc:
static-path-pattern: /res/**
web:
resources:
static-locations: [classpath:/haha/]
请注意：指定新的静态资源文件夹的位置之后，springboot默认的就不生效了，也就是说我们要通过我们指定的文件夹的位置去访问静态资源，以前的不能访问
2.1 欢迎页支持
静态资源路径下 index.html
- 可以配置静态资源路径
- 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
resources:
static-locations: [classpath:/haha/]
- controller能处理/index
2.2 自定义 Favicon
favicon.ico 放在静态资源目录下即可，名字必须叫favicon
spring:
# mvc:
# static-path-pattern: /res/** 这个会导致 Favicon 功能失效
2.3、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 {}
给容器中配了什么。
@Configuration(proxyBeanMethods = false)
@Import(EnableWebMvcConfiguration.class)
@EnableConfigurationProperties({ WebMvcProperties.class, ResourceProperties.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
1、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;
}
2、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;
}
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));
}
//静态资源路径从配置文件中拿，拿不到有四个默认路径
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
有四个默认静态资源路径
@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;
3、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) {
//这里底层写死了欢迎页的访问路径
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");
}
}
4、favicon
浏览器会发送 /favicon 请求获取到图标，整个session期间不再获取，因此静态资源文件夹下的图标名字是固定的