跨域问题：No ‘Access-Control-Allow-Origin‘

Access to XMLHttpRequest at 'http://localhost:8001/ad/getAdsBySpaceId/1' from origin 'http://localhost:8080' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

解决方法：在Controller中加入注解@CrossOrigin

@RestController
@CrossOrigin
public class AdController {


}