code: @Override
      public void addResourceHandlers(ResourceHandlerRegistry registry) {
  
          registry
                  .addResourceHandler("/rs/**")
                  .addResourceLocations("/rs/");
          registry
                  .addResourceHandler("/webjars/**")
                  .addResourceLocations("/webjars/")
                  .resourceChain(true);
      }
docs: Makes static resources within webjars (i.e. JavaScript) available from a browser.  Solution
  based on this article:  http://www.baeldung.com/maven-webjars.