apollo-common/src/main/java/com/ctrip/framework/apollo/common/controller/WebMvcConfig.java/WebMvcConfig/addCacheControl
class WebMvcConfig:  private void addCacheControl(ResourceHandlerRegistry registry, String folder, int cachePeriod) {
    registry.addResourceHandler(String.format("/%s/**", folder))
        .addResourceLocations(String.format("classpath:/static/%s/", folder))
        .setCachePeriod(cachePeriod);
  }