Swagger 2.x JaxrsAnnotationScanner does not find resource classes located in ear

Question

I am currently trying to document an existing API with swagger core. I use swagger core 2.7 and resteasy 3 since I am deploying on wildfly 10. I have a war containing my rest servlet and some model classes located in an ear which also contains the war. The model classes are annoted with @Schema and therefore need a dependency on swagger-annotations. I followed the tutorial on https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X---Integration-and-configuration

So I added the dependency to my war's pom.xml and the annotation module dependency to my module containing the model classes. It compiles and deploys, but when I browse to /myapp/openapi.yaml I see following warnings in the wildfly console for each resource which I defined in web.xml (except the ones contained in the war)

12:52:22,058 WARN [io.swagger.v3.jaxrs2.integration.JaxrsAnnotationScanner] (default task-5) error loading class from resourceClasses: at.prismasolutions.test.render.RPlotFormatParam from [Module "deployment.rserve-test.ear.at.prismasolutions.test.rserve.web-0.0.1-wildfly-SNAPSHOT.war:main" from Service Module Loader]: java.lang.ClassNotFoundException: at.prismasolutions.test.render.RPlotFormatParam from [Module "deployment.rserve-test.ear.at.prismasolutions.test.rserve.web-0.0.1-wildfly-SNAPSHOT.war:main" from Service Module Loader] at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:198) at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:363) at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:351) at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:93) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:264) at io.swagger.v3.jaxrs2.integration.JaxrsAnnotationScanner.classes(JaxrsAnnotationScanner.java:68) at io.swagger.v3.oas.integration.GenericOpenApiContext.read(GenericOpenApiContext.java:470) at io.swagger.v3.jaxrs2.integration.resources.BaseOpenApiResource.getOpenApi(BaseOpenApiResource.java:49) at io.swagger.v3.jaxrs2.integration.resources.OpenApiResource.getOpenApi(OpenApiResource.java:32) at io.swagger.v3.jaxrs2.integration.resources.OpenApiResource$Proxy$_$$_WeldClientProxy.getOpenApi(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:236) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:402) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:209) at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:53) at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:59) at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50) at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292) at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138) at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135) at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48) at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272) at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81) at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202) at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:805) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

my configuration of web.xml:

    <servlet>
    <servlet-name>rserve-resteasy-servlet</servlet-name>
    <servlet-class>
        org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
    </servlet-class>
    <init-param>
        <param-name>resteasy.servlet.mapping.prefix</param-name>
        <param-value>/</param-value>
    </init-param>
    <!-- specify scanner implementation -->
    <init-param>
        <param-name>openApi.configuration.scannerClass</param-name>
        <param-value>io.swagger.v3.jaxrs2.integration.JaxrsAnnotationScanner</param-value>
    </init-param>
    <!-- pretty print -->
    <init-param>
        <param-name>openApi.configuration.prettyPrint</param-name>
        <param-value>true</param-value>
    </init-param>
    <!-- specify resource classes to scan -->
    <init-param>
        <param-name>openApi.configuration.resourceClasses</param-name>
        <param-value>
        rserve.web.RService,
        at.prismasolutions.test.RServeBean.evaluation.REvaluationObject,
        at.prismasolutions.test.RServeBean.evaluation.optima.REvaluationObservationObject,
        at.prismasolutions.test.render.RPlotFormatParam
        </param-value>
    </init-param>
</servlet>

Only rserve.web.RService is found which is located in the war file. Has anyone experience with setting up swagger using resources from a containing ear?

I'm having the same sort of problem. I have a skinny WAR setup and seems to be causing these class loading issues. Out of ideas of what else to try. Filled with every permutation of config available in web.xml, but no luck yet — leonardseymore

Manuel Waltschek Manuel Waltschek · Accepted Answer · 2020-02-13T09:27:41

Sadly I cannot remember which steps actually led to resolving this issue, but I ended up with removing the resourceClasses from the web.xml (except the service endpoint class resource RService which was contained in the war)

I am not using any derivate of javax.ws.rs.Application but instead register resources with the param resteasy.scan

my web.xml configuration contains

<context-param>
    <param-name>resteasy.scan</param-name>
    <param-value>true</param-value>
</context-param>

    <listener>
    <listener-class>
        org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
</listener>
<servlet>
    <servlet-name>rserve-resteasy-servlet</servlet-name>
    <servlet-class>
        org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
    <init-param>
        <param-name>resteasy.servlet.mapping.prefix</param-name>
        <param-value>/</param-value>
    </init-param>
    <!-- specify scanner implementation -->
    <init-param>
        <param-name>openApi.configuration.scannerClass</param-name>
        <param-value>io.swagger.v3.jaxrs2.integration.JaxrsAnnotationScanner</param-value>
    </init-param>
    <!-- pretty print -->
    <init-param>
        <param-name>openApi.configuration.prettyPrint</param-name>
        <param-value>true</param-value>
    </init-param>
    <!-- specify resource classes to scan -->
    <init-param>
        <param-name>openApi.configuration.resourceClasses</param-name>
        <param-value> rweb.RService </param-value>
    </init-param>
</servlet>

Take a look at:

resteasy swagger core example

Also consider checking common mistakes with poor dependency management which might have been my problem back then:

e.g. jboss classloading: classes in ear cannot reference classes that were loaded by the war classloader

class dependencies reference different classes since they were registered twice (war classloader, ear classloader)

Swagger 2.x JaxrsAnnotationScanner does not find resource classes located in ear

1 Answers