Spring WebFlux doesn't handle redirect: directives when media type is requested [SPR-15291]

Greg Turnquist opened SPR-15291 and commented

The following code…

@Controller
public class WelcomeController {

    @GetMapping("/")
    @ResponseBody
    public String welcome() {
        return "Hello World";
    }

    @GetMapping("/redir")
    public Mono<String> redir() {
        return Mono.just("redirect:/");
    }
}

generates the following stacktrace…

java.lang.IllegalStateException: Could not resolve view with name 'redirect:/'.
    at org.springframework.web.reactive.result.view.ViewResolutionResultHandler.lambda$resolveViews$5(ViewResolutionResultHandler.java:274)

---

Affects: 5.0 M5

Issue Links:

• #19103 Reactive HTTP response based RedirectView

Referenced from: commits https://github.com/spring-projects/spring-framework/commit/226c9f9a73d9468b5c0b1c7dfc35700619e06386, https://github.com/spring-projects/spring-framework/commit/718162b8c428220f4cb9c86092c9c651dec6e71c

[spring-projects-issues]

Brian Clozel commented

Since you may have multiple file types associated with this endpoint, maybe dealing with the response “manually” is the best choice:

@GetMapping("/image.jpg")
public Mono<Void> redir(ServerWebExchange exchange) {
	ServerHttpResponse response = exchange.getResponse();
	response.setStatusCode(HttpStatus.SEE_OTHER);
	response.getHeaders().add(HttpHeaders.LOCATION, "/");
	return response.setComplete();
}

[spring-projects-issues]

Rossen Stoyanchev commented

This looks like a bug. Arguably content negotiation should not impact redirects and I recall this being an issue once for Spring MVC (see #13254) and WebFlux should be consistent.

On the Spring MVC side SmartView extends View. I think in WebFlux we can add isRedirect to View as a default method and then it should be easy for ViewResolutionResultHandler to check if a candidate view is a redirect.