Feature/webflux

[ligasgr]

What's this PR do/fix?

This PR provides support for webflux.

Are there unit tests? If not how should this be manually tested?

Existing unit tests were preserved and are still working. Added simplest contract tests for webflux.

Any background context you want to provide?

This PR supersedes PR #2233. It includes all the original changes plus necessary fixes and tests.

Not all of the tests moved in the original PR into the new project were easy to move back. The remaining ones would require creating a new layer of mixins that would not be tied to specific implementation (mvc/webflux). Unfortunately I don’t have that much time available to work on it.

Existing annotation was renamed @EnableSwagger2 -> @ EnableSwagger2WebMvc
and new annotation @EnableSwagger2WebFlux was added.

Please note that it is no longer enough to add dependency on:

<dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.9.2</version> </dependency> 

you now also have to include either:

<dependency> <groupId>io.springfox</groupId> <artifactId>springfox-spring-webmvc</artifactId> <version>2.9.2</version> </dependency> 

or

<dependency> <groupId>io.springfox</groupId> <artifactId>springfox-spring-webflux</artifactId> <version>2.9.2</version> </dependency> 

Documentation needs a lot of updates about dependencies and an example for web flux. The section 4.2. Component Model also needs an update.

What are the relevant issues?

#1773
#2233

[codecov]

Codecov Report

Merging #2608 into master will decrease coverage by 0.39%.
The diff coverage is 78.78%.

@@ Coverage Diff @@ ## master #2608 +/- ## =========================================== - Coverage 95.15% 94.75% -0.4%  - Complexity 3105 3175 +70  =========================================== Files 343 359 +16 Lines 7863 8030 +167 Branches 599 614 +15 =========================================== + Hits 7482 7609 +127  - Misses 235 268 +33  - Partials 146 153 +7

[dilipkrish]

@ligasgr this is a terrific PR! It was one of the few PR's that is so easy to follow the changes. I'll polish and pull it in 🤘

[dilipkrish]

@ligasgr Trying to close this I encountered one potential problem, would love to bounce that idea with you and possibly @deblockt

The PathProvider we have now has web mvc or web flux avatars. Now when we have an application that has both, which one do we pick when used in common infrastructure code for e.g. here

[ligasgr]

@dilipkrish Thanks for your kind words :) And sorry for late response.

Regarding the PathProvider... it would be fairly simple to have the correct PathProviderFactory wired into the correct context by making it a @Bean in the correct configuration class, e.g. WebFluxRelativePathProviderFactory inside of SpringfoxWebFluxConfiguration.

This will not provide a solution to the issue of what the system should do when you have both spring-webmvc and spring-webflux on the classpath. There's a number of questions that need to be answered:

• Should the library be able to scan from both controller types (webmvc & webflux) annotated with appropriate annotations inside of the same application?
• Should it just assume that if there is a servlet context (which will hold true for webflux on tomcat/jetty/servlet 3.1 container) then it should use the provider which uses servlet context to obtain the path?
• Should it somehow allow overriding that?

Currently applied solution avoids answering this stuff and requires exclusion of the "other dependency" which can be seen in contract test projects.
Please let me know your thoughts and I can help amending it to the expected behaviour as long as it is not a fundamental change.

[dilipkrish]

@ligasgr I've merged it to master. Thank you and @deblockt very much for your contribution and efforts!

I still have an outstanding question. I havent experimented or played with it yet, there is the Swagger2ControllerWebFlux and Swagger2ControllerWebMvc, I dont know how they'd behave when they co-exist. Will it throw a duplicate request mapping exception?

[ligasgr]

@dilipkrish Thanks! Can't wait for the official release :) 👍
Right now when e.g. you bring up the context which is configured for webflux and have webmvc on the classpath, you will get an exception when starting up:

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcRequestHandlerProvider' defined in file [/Users/ligasgr/wrk/springfox/springfox-spring-webmvc/out/production/classes/springfox/documentation/spring/web/plugins/WebMvcRequestHandlerProvider.class]: Unsatisfied dependency expressed through constructor parameter 1; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'java.util.List<org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732)	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:197)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1276)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1133)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503)	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760)	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869)	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)	at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:88)	at springfox.petstore.webflux.Server.applicationContext(Server.java:60)	at springfox.petstore.webflux.Server.main(Server.java:21) Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'java.util.List<org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1509)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065)	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:818)	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:724)	... 15 more 

So this is just a first step. Once that issue will be sorted out it will get to the problem that you described before - not able to find the correct PathProviderFactory - there are two so you get the appropriate exception about non unique bean:

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'documentationPluginsBootstrapper' defined in file [/Users/ligasgr/wrk/springfox/springfox-spring-web/out/production/classes/springfox/documentation/spring/web/plugins/DocumentationPluginsBootstrapper.class]: Unsatisfied dependency expressed through constructor parameter 6; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'springfox.documentation.spring.web.paths.PathProviderFactory' available: expected single matching bean but found 2: webFluxRelativePathProviderFactory,webMvcRelativePathProviderFactory	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732)	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:197)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1276)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1133)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503)	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317)	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315)	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760)	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869)	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)	at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:88)	at springfox.petstore.webflux.Server.applicationContext(Server.java:60)	at springfox.petstore.webflux.Server.main(Server.java:21) Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'springfox.documentation.spring.web.paths.PathProviderFactory' available: expected single matching bean but found 2: webFluxRelativePathProviderFactory,webMvcRelativePathProviderFactory	at org.springframework.beans.factory.config.DependencyDescriptor.resolveNotUnique(DependencyDescriptor.java:215)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1116)	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065)	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:818)	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:724)	... 15 more 

Btw. I now know that in situation when e.g. you use embedded tomcat as per instructions from webflux you still will not have the ServletContext available in the context so the factory fails:

org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'javax.servlet.ServletContext' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {} 

If you exclude the WebMvcRelativePathProviderFactory from component scanning the context will start up fine and work fine.

If you have both webmvc and webflux on your classpath and you're trying to use spring-boot-starter-webflux the context will not start up as it will complain about various reasons depending on your config but an example will be:

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:155) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at springfox.petstore.webflux.AppConfig.main(AppConfig.java:35) [classes/:na] Caused by: org.springframework.context.ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean.	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getWebServerFactory(ServletWebServerApplicationContext.java:204) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:178) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]	... 8 common frames omitted 

If you manually create a context without involving spring-boot-starter-webflux and use spring-boot-autoconfigure then your context will start up fine even when you have webmvc and webflux on the classpath.

But the moment you have both @EnableSwagger2WebFlux and @EnableSwagger2WebMvc in your config you will start getting exception like:

Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'webHandler' available	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:686)	at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1210)	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204)	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1095)	at org.springframework.web.server.adapter.WebHttpHandlerBuilder.applicationContext(WebHttpHandlerBuilder.java:161)	at springfox.petstore.webflux.Server.applicationContext(Server.java:59)	at springfox.petstore.webflux.Server.main(Server.java:17) 

Hope this helps answering your questions...
I don't think that it is generally a good idea to mix the two configurations (webmvc and webflux) in one app and I can't really imagine a use case for that.
If you can come up with a reasonable sample app the works fine normally (without springfox) that uses both webmvc and webflux then I can have a go at making it work for springfox.

Thanks,
Grzegorz

[IsaacDeLaRosa]

Hi! thank you so much for supporting webflux!
I am trying to auto generate reactive/reactor classes using springfox.
I added the required dependencies and the @EnableSwagger2WebFlux to my Configuration class. how and where can I define if the auto gen controller will be a Mono or Flux for example? because right now its neither of them.

[dilipkrish]

@IsaacDeLaRosa I'll write up the documentation in a bit, but you would also need to add the spring-web dependency if you havent already added it. What are you seeing can you elaborate?