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TemplateModelProxyHandler using wrong ClassLoader in OSGi Setup

See original GitHub issue

Hi Folks,

I set up a minimal working Vaadin / OSGi (Karaf) Example. Everything works fine util I use the PolymerTemplate (e.g. when Using a Custom Style for my Page). Now, I get the following exception:

There was an exception while trying to navigate to '' with the exception message 'Unable to create an instance of 'org.pragmaticindustries.cockpit.DesktopTemplate'. The constructor threw an exception.'

java.lang.IllegalArgumentException: Unable to create an instance of 'org.pragmaticindustries.cockpit.DesktopTemplate'. The constructor threw an exception.
	at com.vaadin.flow.internal.ReflectTools.createProxyInstance(ReflectTools.java:510)
	at com.vaadin.flow.internal.ReflectTools.createInstance(ReflectTools.java:447)
	at com.vaadin.flow.di.DefaultInstantiator.getOrCreate(DefaultInstantiator.java:65)
	at com.vaadin.flow.di.Instantiator.createRouteTarget(Instantiator.java:158)
	at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.lambda$getRouteTarget$1(AbstractNavigationStateRenderer.java:121)
	at java.util.Optional.orElseGet(Optional.java:267)
	at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.getRouteTarget(AbstractNavigationStateRenderer.java:120)
	at com.vaadin.flow.router.internal.AbstractNavigationStateRenderer.handle(AbstractNavigationStateRenderer.java:178)
	at com.vaadin.flow.router.Router.handleNavigation(Router.java:219)
	at com.vaadin.flow.router.Router.navigate(Router.java:190)
	at com.vaadin.flow.router.Router.initializeUI(Router.java:92)
	at com.vaadin.flow.server.BootstrapHandler.createAndInitUI(BootstrapHandler.java:1117)
	at com.vaadin.flow.server.BootstrapHandler.synchronizedHandleRequest(BootstrapHandler.java:396)
	at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
	at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1507)
	at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:242)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:852)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1604)
	at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:226)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1591)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:542)
	at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:536)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1581)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1307)
	at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:293)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:482)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1549)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1204)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.Server.handle(Server.java:494)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:374)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:268)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:367)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:782)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:918)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
	at com.vaadin.flow.internal.ReflectTools.createProxyInstance(ReflectTools.java:479)
	... 52 more
Caused by: java.lang.NoClassDefFoundError: Lcom/vaadin/flow/internal/StateNode;
	at java.lang.Class.getDeclaredFields0(Native Method)
	at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
	at java.lang.Class.getDeclaredField(Class.java:2068)
	at net.bytebuddy.implementation.LoadedTypeInitializer$ForStaticField.onLoad(LoadedTypeInitializer.java:120)
	at net.bytebuddy.implementation.LoadedTypeInitializer$Compound.onLoad(LoadedTypeInitializer.java:187)
	at net.bytebuddy.dynamic.TypeResolutionStrategy$Passive.initialize(TypeResolutionStrategy.java:102)
	at net.bytebuddy.dynamic.DynamicType$Default$Unloaded.load(DynamicType.java:5623)
	at com.vaadin.flow.templatemodel.TemplateModelProxyHandler.createProxyConstructor(TemplateModelProxyHandler.java:247)
	at com.vaadin.flow.templatemodel.TemplateModelProxyHandler.createInterfaceConstructor(TemplateModelProxyHandler.java:213)
	at com.vaadin.flow.templatemodel.TemplateModelProxyHandler.createProxyConstructor(TemplateModelProxyHandler.java:202)
	at com.vaadin.flow.internal.ReflectionCache.lambda$wrapValueProvider$d0062d93$1(ReflectionCache.java:84)
	at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
	at com.vaadin.flow.internal.ReflectionCache.get(ReflectionCache.java:101)
	at com.vaadin.flow.templatemodel.TemplateModelProxyHandler.createModelProxy(TemplateModelProxyHandler.java:193)
	at com.vaadin.flow.component.polymertemplate.PolymerTemplate.createTemplateModelInstance(PolymerTemplate.java:205)
	at com.vaadin.flow.component.polymertemplate.PolymerTemplate.getModel(PolymerTemplate.java:197)
	at com.vaadin.flow.component.polymertemplate.PolymerTemplate.initModel(PolymerTemplate.java:228)
	at com.vaadin.flow.component.polymertemplate.PolymerTemplate.<init>(PolymerTemplate.java:114)
	at com.vaadin.flow.component.polymertemplate.PolymerTemplate.<init>(PolymerTemplate.java:122)
	at org.pragmaticindustries.cockpit.DesktopTemplate.<init>(DesktopTemplate.java:55)
	... 57 more
Caused by: java.lang.ClassNotFoundException: com.vaadin.flow.internal.StateNode
	at net.bytebuddy.dynamic.loading.ByteArrayClassLoader.findClass(ByteArrayClassLoader.java:347)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 77 more

I did some research and all my Classloading and OSGi Setup seems valid. When going through the Code I saw that the TemplateModelProxy handler uses ByteBuddy in the createProxyConstructor(ClassLoader classLoader, Builder<?> proxyBuilder, String classFqn) Method. Here make() (TemplateModelProxyHandler:246) is called with no parameters which leads ByteBuddy to use an Implemementation with the “default” parameters make(typeResolutionStrategy, TypePool.ClassLoading.ofSystemLoader()) (in SubclassDynamicTypeBuilder:189).

This then messes everything up, as the SystemClassloader is of course pretty empty in OSGi Setup.

So I guess givin the proper parameters to the make() call could / should fix this issue. Until then, no usage of Polymertemplates on OSGi should be possible, sadly.