springboot如何通过URL方式访问外部资源

@Configuration
    public class MyWebMvcConfigurer extends WebMvcConfigurationSupport {
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            //   访问相对路径
            registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");
            //   访问绝对路径 访问路径和 存放路径可以自定义，建议存放路径放到配置文件中
            registry.addResourceHandler("/img/**").addResourceLocations("file:D:/img/");
            super.addResourceHandlers(registry);
        }
    }

localhost:8080/assets/文件名.后缀
localhost:8080/img/文件名.后缀