Running Spring Webflux Application as a WAR

Question

I have a Spring reactive sample application that was modified from one of the examples that was provided in the the Spring Webflux documentation. The master branch of this application uses Spring Boot in the traditional manner, with an embedded application server (Netty). It is working fine.

In the Liberty branch, I am trying to build the application as a WAR and deploy to Websphere Liberty Profile. Aside from changes to the build process, the most significant code change is having my Application.java (source here) extend AbstractAnnotationConfigDispatcherHandlerInitializer, as per Webflux documentation:

For Servlet containers especially with WAR deployment you can use the AbstractAnnotationConfigDispatcherHandlerInitializer which as a WebApplicationInitializer and is auto-detected by Servlet containers. It takes care of registering the ServletHttpHandlerAdapter as shown above. You will need to implement one abstract method in order to point to your Spring configuration.

However, when I do this, none of my resources/endpoints get mapped and none of my beans that I declare in Application.java are registered. This is the full output that I get, with the exception being thrown when trying to access the context root:

13:29:48.848 [Default Executor-thread-6] DEBUG org.springframework.context.annotation.ClassPathBeanDefinitionScanner - JSR-250 'javax.annotation.ManagedBean' found and supported for component scanning
13:29:48.855 [Default Executor-thread-6] INFO org.springframework.context.annotation.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@4ba0f9a4: startup date [Fri Oct 13 13:29:48 CDT 2017]; root of context hierarchy
13:29:48.857 [Default Executor-thread-6] DEBUG org.springframework.context.annotation.AnnotationConfigApplicationContext - Bean factory for org.springframework.context.annotation.AnnotationConfigApplicationContext@4ba0f9a4: org.springframework.beans.factory.support.DefaultListableBeanFactory@41daf3ea: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory]; root of factory hierarchy
13:29:48.907 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
13:29:48.907 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
13:29:48.939 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor' to allow for resolving potential circular references
13:29:48.943 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
13:29:49.371 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
13:29:49.371 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
13:29:49.372 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor' to allow for resolving potential circular references
13:29:49.425 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
13:29:49.426 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
13:29:49.426 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
13:29:49.428 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor' to allow for resolving potential circular references
13:29:49.432 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
13:29:49.433 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.annotation.internalCommonAnnotationProcessor'
13:29:49.433 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.annotation.internalCommonAnnotationProcessor'
13:29:49.441 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.annotation.internalCommonAnnotationProcessor' to allow for resolving potential circular references
13:29:49.450 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.annotation.internalCommonAnnotationProcessor'
13:29:49.454 [Default Executor-thread-6] DEBUG org.springframework.context.annotation.AnnotationConfigApplicationContext - Unable to locate MessageSource with name 'messageSource': using default [org.springframework.context.support.DelegatingMessageSource@5c88ddc5]
13:29:49.458 [Default Executor-thread-6] DEBUG org.springframework.context.annotation.AnnotationConfigApplicationContext - Unable to locate ApplicationEventMulticaster with name 'applicationEventMulticaster': using default [org.springframework.context.event.SimpleApplicationEventMulticaster@6a00d295]
13:29:49.461 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@41daf3ea: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory]; root of factory hierarchy
13:29:49.462 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
13:29:49.462 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
13:29:49.462 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
13:29:49.463 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.annotation.internalCommonAnnotationProcessor'
13:29:49.463 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.event.internalEventListenerProcessor'
13:29:49.463 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.event.internalEventListenerProcessor'
13:29:49.477 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.event.internalEventListenerProcessor' to allow for resolving potential circular references
13:29:49.479 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.event.internalEventListenerProcessor'
13:29:49.480 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating shared instance of singleton bean 'org.springframework.context.event.internalEventListenerFactory'
13:29:49.480 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Creating instance of bean 'org.springframework.context.event.internalEventListenerFactory'
13:29:49.481 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Eagerly caching bean 'org.springframework.context.event.internalEventListenerFactory' to allow for resolving potential circular references
13:29:49.483 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Finished creating instance of bean 'org.springframework.context.event.internalEventListenerFactory'
13:29:49.484 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.context.event.internalEventListenerFactory'
13:29:49.514 [Default Executor-thread-6] DEBUG org.springframework.context.annotation.AnnotationConfigApplicationContext - Unable to locate LifecycleProcessor with name 'lifecycleProcessor': using default [org.springframework.context.support.DefaultLifecycleProcessor@6ffc157d]
13:29:49.515 [Default Executor-thread-6] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'lifecycleProcessor'
13:29:49.520 [Default Executor-thread-6] DEBUG org.springframework.core.env.PropertySourcesPropertyResolver - Could not find key 'spring.liveBeansView.mbeanDomain' in any property source
[AUDIT   ] CWWKZ0001I: Application spring-reactive-playground started in 3.480 seconds.
[AUDIT   ] CWWKF0012I: The server installed the following features: [servlet-3.1, websocket-1.1].
[AUDIT   ] CWWKF0011I: The server LibertyProjectServer is ready to run a smarter planet.
13:30:05.943 [Default Executor-thread-14] DEBUG reactor.util.Loggers$LoggerFactory - Using Slf4j logging framework
13:30:05.994 [Default Executor-thread-14] DEBUG org.springframework.web.reactive.DispatcherHandler - Processing GET request for [http://localhost:9080/]
13:30:06.041 [Default Executor-thread-14] ERROR org.springframework.web.server.adapter.HttpWebHandlerAdapter - Failed to handle request
org.springframework.web.server.ResponseStatusException: Response status 404 with reason "No matching handler"
        at org.springframework.web.reactive.DispatcherHandler.<clinit>(DispatcherHandler.java:74)
        at org.springframework.web.reactive.support.AbstractDispatcherHandlerInitializer.createDispatcherHandler(AbstractDispatcherHandlerInitializer.java:145)
        at org.springframework.web.reactive.support.AbstractDispatcherHandlerInitializer.registerDispatcherHandler(AbstractDispatcherHandlerInitializer.java:90)
        at org.springframework.web.reactive.support.AbstractDispatcherHandlerInitializer.onStartup(AbstractDispatcherHandlerInitializer.java:63)
        at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:172)
        at com.ibm.ws.webcontainer.webapp.WebApp.initializeServletContainerInitializers(WebApp.java:2539)
        at com.ibm.ws.webcontainer.webapp.WebApp.initialize(WebApp.java:1055)
        at com.ibm.ws.webcontainer.webapp.WebApp.initialize(WebApp.java:6595)
        at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost.startWebApp(DynamicVirtualHost.java:468)
        at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost.startWebApplication(DynamicVirtualHost.java:463)
        at com.ibm.ws.webcontainer.osgi.WebContainer.startWebApplication(WebContainer.java:1120)
        at com.ibm.ws.webcontainer.osgi.WebContainer.startModule(WebContainer.java:925)
        at com.ibm.ws.app.manager.module.internal.ModuleHandlerBase.deployModule(ModuleHandlerBase.java:100)
        at com.ibm.ws.app.manager.module.internal.DeployedModuleInfoImpl.installModule(DeployedModuleInfoImpl.java:50)
        at com.ibm.ws.app.manager.module.internal.DeployedAppInfoBase.deployModules(DeployedAppInfoBase.java:420)
        at com.ibm.ws.app.manager.module.internal.DeployedAppInfoBase.deployApp(DeployedAppInfoBase.java:406)
        at com.ibm.ws.app.manager.war.internal.WARApplicationHandlerImpl.install(WARApplicationHandlerImpl.java:66)
        at com.ibm.ws.app.manager.internal.statemachine.StartAction.execute(StartAction.java:141)
        at com.ibm.ws.app.manager.internal.statemachine.ApplicationStateMachineImpl.enterState(ApplicationStateMachineImpl.java:1259)
        at com.ibm.ws.app.manager.internal.statemachine.ApplicationStateMachineImpl.run(ApplicationStateMachineImpl.java:874)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:748)

I have also tried deploying to Tomcat 9 and I get the same problem. I have previously successfully deployed traditional Spring MVC applications as a WAR by extending SpringBootServletInitializer instead of AbstractAnnotationConfigDispatcherHandlerInitializer. What is the equivalent process for Spring Webflux applications? What am I missing in my project code?

Answer 1

Spring 5 brings some variants of WebApplicationInitializer for webflux based applications.

Before Spring 5.0.2(Spring Boot 2.0.0.M7 aligned with this version), there is a bug in AbstractAnnotationConfigDispatcherHandlerInitializer, and in 5.0.2, this class is marked as @Deprecated, there is a new AbstractReactiveWebInitializer introduced. But this class seems also buggy, I have to override the createApplicationContext() to make it work. See the comments in my sample AppInitializer for more details.

Check my workable war sample which was tested successfully on tomcat.