Wiring in image ownership

Spring WebFlux's ServerWebExchange comes prepared for security by providing a getPrincipal() API that returns Mono<Principal>. While the default version, straight out of Spring Framework, supplies Mono.empty(), Spring Security automatically hooks in a filter to supply a real value via WebSessionSecurityContextRepository.

With Spring Security and Spring Session hooked into all our web calls, we can leverage this information every time a new image is uploaded.

First of all, we can adjust our Image domain object as follows:

    @Data 
    @AllArgsConstructor 
    public class Image { 
 
      @Id private String id; 
      private String name; 
      private String owner; 
    } 

This last code is the same POJO that we've used throughout this book with one change:

• It now has a String owner property. This lets us associate an image with whoever uploaded it (which we'll see shortly).

Spring Security makes it possible to inject any Spring WebFlux controller with an authentication...