gateway+oauth2 error

[yqbjtu]

I have the same issue, I just made a small modification in spring-cloud-gateway-sample. only adding the following two dependencies for I need to support oauth (if I does not use gateway , my oauth works well).

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
		<groupId>org.springframework.security.oauth.boot</groupId>
		<artifactId>spring-security-oauth2-autoconfigure</artifactId>
		<version>2.0.0.RELEASE</version>
		</dependency>

then I added "@EnableOAuth2Sso" to main class. When I start my gateway project. it reports the following error:
...
java.lang.Thread.run(Thread.java:748)
2018-08-08 19:46:09.047 WARN 16540 --- [ost-startStop-1] o.a.c.loader.WebappClassLoaderBase : The web application [ROOT] appears to have started a thread named [reactor-http-nio-7] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(WindowsSelectorImpl.java:296)
sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(WindowsSelectorImpl.java:278)
sun.nio.ch.WindowsSelectorImpl.doSelect(WindowsSelectorImpl.java:159)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62)
io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409)
io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
java.lang.Thread.run(Thread.java:748)
2018-08-08 19:46:09.047 WARN 16540 --- [ost-startStop-1] o.a.c.loader.WebappClassLoaderBase : The web application [ROOT] appears to have started a thread named [reactor-http-nio-8] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(WindowsSelectorImpl.java:296)
sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(WindowsSelectorImpl.java:278)
sun.nio.ch.WindowsSelectorImpl.doSelect(WindowsSelectorImpl.java:159)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62)
io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409)
io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
java.lang.Thread.run(Thread.java:748)
2018-08-08 19:46:09.051 WARN 16540 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
2018-08-08 19:46:09.060 INFO 16540 --- [ main] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-08-08 19:46:09.194 ERROR 16540 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :

---

APPLICATION FAILED TO START

---

Description:

Parameter 0 of method hystrixGatewayFilterFactory in org.springframework.cloud.gateway.config.GatewayAutoConfiguration$HystrixConfiguration required a bean of type 'org.springframework.web.reactive.DispatcherHandler' that could not be found.

Action:

Consider defining a bean of type 'org.springframework.web.reactive.DispatcherHandler' in your configuration.

Process finished with exit code 1
...

If I remove the spring-boot-starter-web

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

when I started ,the error is like this

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [com.example.demogateway.DemogatewayApplication]; nested exception is java.lang.IllegalStateException: Failed to introspect annotated methods on class org.springframework.security.oauth2.config.annotation.web.configuration.OAuth2ClientConfiguration
...
Caused by: java.lang.NoClassDefFoundError: javax/servlet/Filter

then I added javax.servlet-api dependeancy, the new error is like this.

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-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.6.RELEASE.jar:5.0.6.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at com.example.demogateway.DemogatewayApplication.main(DemogatewayApplication.java:80) [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-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:178) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.2.RELEASE.jar:2.0.2.RELEASE]
	... 8 common frames omitted

Notes:
When the gateway runs standalone, it start netty,
When my oauth runs standalone,it start tomcat,
How to integrate gateway and oauth?

Apprecate your help!
You can see my code here.

[smitchell]

@yqbjtu - Did you get @EnableOAuth2Sso working with Spring Cloud Gateway?