webjars & 静态资源文件夹

 

WebMvcAutoConfiguration

添加资源映射：

        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            if (!this.resourceProperties.isAddMappings()) {
                logger.debug("Default resource handling disabled");
            } else {
                Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
                CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
                if (!registry.hasMappingForPattern("/webjars/**")) {
                    this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{"/webjars/**"}).addResourceLocations(new String[]{"classpath:/META-INF/resources/webjars/"}).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));
                }

                String staticPathPattern = this.mvcProperties.getStaticPathPattern();
                if (!registry.hasMappingForPattern(staticPathPattern)) {
                    this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{staticPathPattern}).addResourceLocations(WebMvcAutoConfiguration.getResourceLocations(this.resourceProperties.getStaticLocations())).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));
                }

            }
        }

所有"/webjars/**"路径 ， 都去类路径下 classpath: /META-INF/resources/webjars/ 找资源， 

所以就是
http://localhost:8080/webjars/jquery/3.5.1/jquery.js
能访问

/META-INF/resources/webjars/jquery/3.5.1/jquery.js 路径的文件

1) webjars： 以jar包的方式引入静态资源
什么是webjar?
搜索webjar， 可以将jquery用pom引入：

 

 

 引入， 正好对应这个映射：

 

 

 

结果是的：

 

 

2) springboot对静态资源的映射规则：
看代码：
还是
WebMvcAutoConfiguration的这个方法

public void addResourceHandlers(ResourceHandlerRegistry registry) {
    if (!this.resourceProperties.isAddMappings()) {
        logger.debug("Default resource handling disabled");
    } else {
        Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
        CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
        if (!registry.hasMappingForPattern("/webjars/**")) {
            this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{"/webjars/**"}).addResourceLocations(new String[]{"classpath:/META-INF/resources/webjars/"}).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));
        }

        String staticPathPattern = this.mvcProperties.getStaticPathPattern();
        if (!registry.hasMappingForPattern(staticPathPattern)) {
            this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{staticPathPattern}).addResourceLocations(WebMvcAutoConfiguration.getResourceLocations(this.resourceProperties.getStaticLocations())).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));
        }

    }
}

 

进去：
WebMvcProperties

    private String staticPathPattern;
    private final WebMvcProperties.Async async;
    private final WebMvcProperties.Servlet servlet;
    private final WebMvcProperties.View view;
    private final WebMvcProperties.Contentnegotiation contentnegotiation;
    private final WebMvcProperties.Pathmatch pathmatch;

    public WebMvcProperties() {
        this.localeResolver = WebMvcProperties.LocaleResolver.ACCEPT_HEADER;
        this.format = new WebMvcProperties.Format();
        this.dispatchTraceRequest = false;
        this.dispatchOptionsRequest = true;
        this.ignoreDefaultModelOnRedirect = true;
        this.publishRequestHandledEvents = true;
        this.throwExceptionIfNoHandlerFound = false;
        this.logResolvedException = false;
        this.staticPathPattern = "/**";
        this.async = new WebMvcProperties.Async();
        this.servlet = new WebMvcProperties.Servlet();
        this.view = new WebMvcProperties.View();
        this.contentnegotiation = new WebMvcProperties.Contentnegotiation();
        this.pathmatch = new WebMvcProperties.Pathmatch();
    }

addResourceLocations(WebMvcAutoConfiguration.getResourceLocations(this.resourceProperties.getStaticLocations())) 这里添加了资源的位置

public class ResourceProperties {
    private static final String[] CLASSPATH_RESOURCE_LOCATIONS = new String[]{"classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/"};
    private String[] staticLocations;
    private boolean addMappings;
    private final ResourceProperties.Chain chain;
    private final ResourceProperties.Cache cache;

    public ResourceProperties() {
        this.staticLocations = CLASSPATH_RESOURCE_LOCATIONS;
        this.addMappings = true;
        this.chain = new ResourceProperties.Chain();
        this.cache = new ResourceProperties.Cache();
    }

"/**"访问当前项目的任何资源， （静态资源的文件夹） ，如果没人处理，会默认去以下几个文件路径下找

// 静态资源文件夹， 这几个都可以存放静态资源：
classpath:/META-INF/resources/
classpath:/resources/"
classpath:/static/"
classpath:/public/

例如 localhost:8080/a/b.js ， 可以到 /META-INF/resources/a/b.js 找

 

 

 

 或者：

/resources/a/b.js找：

 

 

 

 或者类路径下/static/a/b.js找：

 

 

 

 或者/public/a/b.js下找

 

 

 

 

3）欢迎页面： 静态资源文件夹下的所有index.html页面： 被 /**映射

 

 

http://localhost:8080/ 会到以上静态资源文件夹中找index.html页面 

源码有变化，我没明白回头再看

 

结果： 

 

 

 路径：