Redirection issues for spring-webflux [SPR-16704]

[spring-projects-issues]

cafebaby opened SPR-16704 and commented

According to the redirection test described in the official website "WebFlux Reference Documentation", I found that the redirection is not the same as described in the spring MVC format.
For example: "redirect:/some/resource", the access will be reported abnormally when running.

The exception information is as follows:

java.lang.IllegalStateException: Could not resolve view with name 'redirect:/complete'.
	at org.springframework.web.reactive.result.view.ViewResolutionResultHandler.lambda$resolveViews$3(ViewResolutionResultHandler.java:277) ~[spring-webflux-5.0.4.RELEASE.jar:5.0.4.RELEASE]
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:107) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:450) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1069) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:117) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:460) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:349) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onComplete(FluxConcatMap.java:265) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:460) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators.complete(Operators.java:125) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:111) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:61) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxConcatMap.subscribe(FluxConcatMap.java:121) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:450) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:450) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:1626) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.request(FluxOnAssembly.java:532) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:1440) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1314) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onSubscribe(FluxOnAssembly.java:516) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoCallableOnAssembly.subscribe(MonoCallableOnAssembly.java:82) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:450) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1069) ~[reactor-core-3.1.5.RELEASE.jar:3.1.5.RELEASE]

The meaning of the error message is to use the return value as the String type to match the corresponding view instead of selecting the redirect.

By looking at the source code ViewResolutionResultHandler class. Finding the method in the handleResultResult

else if (CharSequence.class.isAssignableFrom(clazz) && !hasModelAnnotation(parameter)) {
	viewsMono = resolveViews(returnValue.toString(), locale);
}
else if (Rendering.class.isAssignableFrom(clazz)) {
	Rendering render = (Rendering) returnValue;
	HttpStatus status = render.status();
	if (status != null) {
		exchange.getResponse().setStatusCode(status);
	}
	exchange.getResponse().getHeaders().putAll(render.headers());
	model.addAllAttributes(render.modelAttributes());
	Object view = render.view();
	if (view == null) {
		view = getDefaultViewName(exchange);
	}

Discovered string is forwarded as view name.

I don't know if I understand right, but at the moment I feel my opinion is right.

---

Affects: 5.0.4

[spring-projects-issues]

Sébastien Deleuze commented

Could you please share a repro project that demonstrates the issue?

[spring-projects-issues]

cafebaby commented

The first time I used this platform, I didn't know how to upload the project. But I'm sure that I modified some of the logic of the ViewResolutionResultHandler class. Now it is OK, but the source code is still not

[spring-projects-issues]

Sébastien Deleuze commented

Redirect is expected to work correctly with WebFlux, so I would need a repro project to understand the issue you face. You can attach a zip file (using the More button) containing the project, put it on a GitHub repository or send a PR on https://github.com/spring-projects/spring-framework-issues.

[spring-projects-issues]

cafebaby commented

my project url:https://github.com/zhouzhou19950825/springwebflux/

[spring-projects-issues]

Rossen Stoyanchev commented

The code for detecting "redirect:" is in UrlBasedViewResolver (same as in Spring MVC BTW). Perhaps you don't have any view resolver configured? So the view name simply remains unresolved.

[spring-projects-issues]

Sébastien Deleuze commented

Indeed, just adding for example spring-boot-starter-mustache dependency makes the redirect working in the repro project.