以这种方式尝试:

public void addResourceHandlers(ResourceHandlerRegistry registry) {
      registry.addResourceHandler("/css/**")
        .addResourceLocations("/css/");
    }

这假设您的目录结构为:

This assumes your directory structure is:

src
  main
      java
      resources
        css
      webapp

重点是您没有在资源处理程序中指定资源级别.

The point is that you don't specify the resources level in your resource handler.