Mapping Rules spring boot static resources (2) resource mapping for him

1. If it is not / webjars / ** Resources

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));
                }

spring boot will look through this method getStaticLocations

   public String[] getStaticLocations() {
        return this.staticLocations;
    }

Return staticLocations resource file by this method

    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();
    }

From here you can see an array

"classpath:/META-INF/resources/", 

"classpath:/resources/", 

"classpath:/static/", 

"classpath:/public/"}

So we can project static files into these folders

 

 

Example: