Re: [Freemarker-devel] freemarker-gae-pre2 - java.lang.VerifyError on GAE

Attila Szegedi <[email protected]>
Newsgroups gmane.comp.web.freemarker.user,gmane.comp.web.freemarker.devel
Message-ID <[email protected]> 
Yes, I contacted a Google Developer Advocate that I'm in touch with and it seems he was able to find an engineer to look into this.

I responded on the GAE group, but I'll repeat the idea here too: since the problem seems to be with the JSP classes that GAE provides, why don't you grab a vanilla JSP JAR file from a Tomcat or Jetty download, and drop it in your webapp's WEB-INF/lib directory? Then the FreeMarker's JSP taglib machinery might[*] be able to load those classes and not the GAE modified JSP classes, and thus work correctly.

[*] Note that it might not work, if GAE overrides the classpath.

Attila.

On 2010.05.03., at 18:25, [email protected] wrote:

> Some one from google is ready to give a look to this issue..
> 
> See the thread http://groups.google.com/group/google-appengine-java/browse_thread/thread/d4e78e3e733a9b2d
> 
> I will try to provide him a sample application on which he can test, however if some one already have/or can create a basic sample and attach to the ticket it would be great.
> 
> http://code.google.com/p/googleappengine/issues/detail?id=3157
>  
>    
> Sudhir Nimavat
> Senior software engineer. 
> Quick start global PVT LTD.
> Baroda - 390007
> Gujarat, India
> http://www.ramanandi.org
> Warning: Spelling errors in this message are the product of a poor school system. Pay teachers more than athletes..
>  
> 
> 
> From: Daniel Dekany <[email protected]>
> To: [email protected]
> Sent: Wed, 28 April, 2010 2:54:22 PM
> Subject: Re: [FreeMarker-user] freemarker-gae-pre2 - java.lang.VerifyError on GAE
> 
> Wednesday, April 28, 2010, 11:04:00 AM, [email protected] wrote:
> 
> > Did you look at the class? I don't see any thing unusual in the
> > code.. Don't understand why it's failing
> 
> Of course it doesn't make sense. But then that's why one has to try
> things. Like, what's if it's not package private. Will it still fail?
> If so, then that's unrelated. So then, next, what if all its method
> bodies are empty, so all unnecessarily imports are removed. Etc.
> 
> BTW, is your test application also minimalist? Stuff like
> framework-specific class loaders, instrumentation, etc. might be the
> culprit. If you have anything like that...
> 
> > May be, because the class is package privat.
> 
> > See the code here
> > http://freemarker.svn.sourceforge.net/viewvc/freemarker/branches/2.3-gae/freemarker/src/freemarker/ext/jsp/FreeMarkerJspApplicationContext.java?revision=1164&view=markup
> >  
> >  
> >  
> >  
> >  
> > Sudhir Nimavat
> > Senior software engineer. 
> > Quick start global PVT LTD.
> > Baroda - 390007 
> > Gujarat, India
> > http://www.jsptube.com
> > Warning: Spelling errors in this message are the product of a poor
> > school system. Pay teachers more than athletes..
> >  
> >
> >
> > From: Daniel Dekany <[email protected]>
> > To: FreeMarker-user <[email protected]>
> > Cc: [email protected]
> > Sent: Wed, 28 April, 2010 1:20:07 PM
> > Subject: Re: [FreeMarker-user] freemarker-gae-pre2 - java.lang.VerifyError on GAE
> >
> > Tuesday, April 27, 2010, 4:02:27 PM, [email protected] wrote:
> >
> >> Yeah, I understand, it's just another weird behavior of GAE. 
> >> But I don't see any option other thn reporting an issue to GAE. (that you already did)
> >
> > Trying to find the *minimal* example where GAE still fails might
> > helps. That probably would include removing tons of classes and lines
> > from FM (or rather, copy pasting from it the little relevant fragment
> > that still fails). Just a blind tip anyway... But once again I
> > wouldn't build any business on the hope that this will be fixed in GAE
> > soon enough. So rather we should introduce a workaround, and so it
> > would be good to find out if what unlucky combination triggers this
> > GAE bug(?).
> >
> >> BTW: 
> >>> As for your suggestion to try to develop a GAE app myself
> >>
> >> He is some another guy who commented on the blog not me ;)  my comment is just above his.
> >>  
> >>  
> >> Sudhir Nimavat
> >> Senior software engineer. 
> >> Quick start global PVT LTD.
> >> Baroda - 390007 
> >> Gujarat, India
> >>
> >> Warning: Spelling errors in this message are the product of a poor
> >> school system. Pay teachers more than athletes..
> >>  
> >>
> >>
> >> From: Attila Szegedi <[email protected]>
> >> To: FreeMarker-user <[email protected]>
> >> Sent: Tue, 27 April, 2010 7:18:27 PM
> >> Subject: Re: [FreeMarker-user] freemarker-gae-pre2 - java.lang.VerifyError on GAE
> >>
> >> Hi,
> >>
> >> as I said on the blog comment thread:
> >>
> >> "I believe NoClassDefFoundError might be a consequence of the
> >> VerifyError; it's the way JVM works -- if loading of a class fails
> >> for whatever reason (including failure to load another class it
> >> depends on during loading), then JVM will remember that it failed to
> >> load the class, and on next attempt, it will quickly fail with
> >> NoClassDefFoundError instead. So, I'd ignore this error for a while
> >> and just go and find the first error that occurred before the
> >> NoClassDefFoundError - that is the real cause of your problem."
> >>
> >> As for your suggestion to try to develop a GAE app myself -
> >> unfortunately, I have no idea how to develop for GAE; never did it.
> >> Not sure I'd have more tools at my disposal to debug the problem
> >> than you do. I think we ultimately have to hammer the GAE team; I'm
> >> fairly certain that FreeMarker is in clear - we're using legal Java
> >> code constructs; all we're running into so far were GAE restrictions.
> >>
> >> Attila.
> >>
> >> On 2010.04.27., at 15:43, [email protected] wrote:
> >>
> >>> What about the another exception NoClassDefFoundError
> >>> Any idea why FreeMarkerPageContext pageContext = PageContextFactory.getCurrentPageContext() throws this ?
> >>> 
> >>> java.lang.NoClassDefFoundError: Could not initialize class freemarker.ext.jsp.PageContextFactory
> >>>    at freemarker.ext.jsp.TagTransformModel.getWriter(TagTransformModel.java:99)
> >>>    at freemarker.core.Environment.visit(Environment.java:286)
> >>>    at freemarker.core.UnifiedCall.accept(UnifiedCall.java:130)
> >>> 
> >>> Thanks
> >>> SN
> >>>  
> >>>  
> >>>  
> >>> 
> >>>  
> >>> Sudhir Nimavat
> >>> Senior software engineer. 
> >>> Quick start global PVT LTD.
> >>> Baroda - 390007
> >>> Gujarat, India
> >>> 
> >>> Warning: Spelling errors in this message are the product of a poor school system. Pay teachers more than athletes..
> >>>  
> >>> 
> >>> 
> >>> From: Attila Szegedi <[email protected]>
> >>> To: FreeMarker-user <[email protected]>
> >>> Sent: Tue, 27 April, 2010 6:05:29 PM
> >>> Subject: Re: [FreeMarker-user] freemarker-gae-pre2 - java.lang.VerifyError on GAE
> >>> 
> >>> I opened a defect report with the GAE: <http://code.google.com/p/googleappengine/issues/detail?id=3157>, described it the best I could.
> >>> 
> >>> Attila.
> >>> 
> >>> On 2010.04.27., at 14:28, Attila Szegedi wrote:
> >>> 
> >>> > Hi Sudhir,
> >>> > 
> >>> > I am sorry to say that I have no idea what does this error message mean. The last point in our code that executes is FreeMarkerJspFactory21.java:13, which evaluates "FreeMarkerJspApplicationContext.class.getName()". Apparently, it will then attempt to load the FreeMarkerJspApplicationContext class, and the class is rejected by Google's verifier with this message "incompatible argument to function".
> >>> > 
> >>> > Now, <init> is automatically generated by the compiler, as the class has no explicit constructor in the source code. It directly subclasses java.lang.Object, so it's not even the case of having some funky superclass. I can't imagine why would this fail... Try pressing with the App Engine developers.
> >>> > 
> >>> > Attila.
> >>> > 
> >>> > On 2010.04.27., at 11:55, [email protected] wrote:
> >>> > 
> >>> >> I am using freemarker-gae-pre2.jar and I get following error when I deploy to GAE. Its working fine on my local machine
> >>> >> I am using spring MVC + freemarker.
> >>> >> Error - 
> >>> >> 
> >>> >> java.lang.VerifyError: (class: freemarker/ext/jsp/FreeMarkerJspApplicationContext, method: <init> signature: ()V) Incompatible argument to function
> >>> >>    at com.google.appengine.runtime.Request.process-814a4fa105eb62da(Request.java)
> >>> >>    at java.lang.Class.forName0(Native Method)
> >>> >>    at java.lang.Class.forName(Class.java:109)
> >>> >>    at freemarker.ext.jsp.FreeMarkerJspFactory21.class$(FreeMarkerJspFactory21.java:13)
> >>> >>    at freemarker.ext.jsp.FreeMarkerJspFactory21.<clinit>(FreeMarkerJspFactory21.java:12)
> >>> >>    at
> >>> >> freemarker.ext.jsp.FreeMarkerPageContext21.<clinit>(FreeMarkerPageContext21.java:30)
> >>> >>    at java.lang.Class.forName0(Native Method)
> >>> >>    at java.lang.Class.forName(Class.java:109)
> >>> >>    at freemarker.ext.jsp.PageContextFactory.getPageContextImpl(PageContextFactory.java:21)
> >>> >>    at
> >>> >> freemarker.ext.jsp.PageContextFactory.<clinit>(PageContextFactory.java:15)
> >>> >> 
> >>> >>    at freemarker.ext.jsp.TagTransformModel.getWriter(TagTransformModel.java:99)
> >>> >>    at freemarker.core.Environment.visit(Environment.java:286)
> >>> >>    at freemarker.core.UnifiedCall.accept(UnifiedCall.java:130)
> >>> >>    at freemarker.core.Environment.visit(Environment.java:210)
> >>> >>    at freemarker.core.Macro$Context.runMacro(Macro.java:172)
> >>> >>    at freemarker.core.Environment.visit(Environment.java:603)
> >>> >>    at freemarker.core.UnifiedCall.accept(UnifiedCall.java:106)
> >>> >>    at freemarker.core.Environment.visit(Environment.java:210)
> >>> >>    at freemarker.core.MixedContent.accept(MixedContent.java:92)
> >>> >>    at
> >>> >> freemarker.core.Environment.visit(Environment.java:210)
> >>> >>    at freemarker.core.Environment.process(Environment.java:190)
> >>> >>    at freemarker.template.Template.process(Template.java:256)
> >>> >>    at
> >>> >> org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:366)
> >>> >> 
> >>> >>    at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283)
> >>> >>    at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233)
> >>> >>    at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167)
> >>> >>    at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
> >>> >>    at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1060)
> >>> >>    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:798)
> >>> >>    at
> >>> >> org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716)
> >>> >>    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
> >>> >>    at
> >>> >> org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
> >>> >> 
> >>> >>    at javax.servlet.http.HttpServlet.service(HttpServlet.java:693)
> >>> >>    at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
> >>> >>    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
> >>> >>    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
> >>> >>    at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:97)
> >>> >>    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> >>> >>    at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
> >>> >>    at
> >>> >> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> >>> >>    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
> >>> >>    at
> >>> >> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> >>> >> 
> >>> >>    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
> >>> >>    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
> >>> >>    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
> >>> >>    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
> >>> >>    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
> >>> >>    at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:238)
> >>> >>    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
> >>> >>    at org.mortbay.jetty.Server.handle(Server.java:326)
> >>> >>    at
> >>> >> org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
> >>> >>    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
> >>> >>    at
> >>> >> com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
> >>> >> 
> >>> >>    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
> >>> >>    at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
> >>> >>    at com.google.apphosting.runtime.JavaRuntime.handleRequest(JavaRuntime.java:243)
> >>> >>    at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:5838)
> >>> >>    at com.google.apphosting.base.RuntimePb$EvaluationRuntime$6.handleBlockingRequest(RuntimePb.java:5836)
> >>> >>    at com.google.net.rpc.impl.BlockingApplicationHandler.handleRequest(BlockingApplicationHandler.java:24)
> >>> >>    at com.google.net.rpc.impl.RpcUtil.runRpcInApplication(RpcUtil.java:398)
> >>> >>    at
> >>> >> com.google.net.rpc.impl.Server$2.run(Server.java:852)
> >>> >>    at com.google.tracing.LocalTraceSpanRunnable.run(LocalTraceSpanRunnable.java:56)
> >>> >>    at
> >>> >> com.google.tracing.LocalTraceSpanBuilder.internalContinueSpan(LocalTraceSpanBuilder.java:576)
> >>> >> 
> >>> >>    at com.google.net.rpc.impl.Server.startRpc(Server.java:807)
> >>> >>    at com.google.net.rpc.impl.Server.processRequest(Server.java:369)
> >>> >>    at com.google.net.rpc.impl.ServerConnection.messageReceived(ServerConnection.java:442)
> >>> >>    at com.google.net.rpc.impl.RpcConnection.parseMessages(RpcConnection.java:319)
> >>> >>    at com.google.net.rpc.impl.RpcConnection.dataReceived(RpcConnection.java:290)
> >>> >>    at com.google.net.async.Connection.handleReadEvent(Connection.java:474)
> >>> >>    at com.google.net.async.EventDispatcher.processNetworkEvents(EventDispatcher.java:831)
> >>> >>    at com.google.net.async.EventDispatcher.internalLoop(EventDispatcher.java:207)
> >>> >>    at com.google.net.async.EventDispatcher.loop(EventDispatcher.java:103)
> >>> >>    at
> >>> >> com.google.net.rpc.RpcService.runUntilServerShutdown(RpcService.java:251)
> >>> >>    at
> >>> >> com.google.apphosting.runtime.JavaRuntime$RpcRunnable.run(JavaRuntime.java:404)
> >>> >> 
> >>> >>    at java.lang.Thread.run(Unknown Source)
> >>> >> 
> >>> >>  Any idea? workaround?
> >>> >> 
> >>> >> 
> >>> >> Sudhir Nimavat
> >>> >> Senior software engineer. 
> >>> >> Quick start global PVT LTD.
> >>> >> Baroda - 390007 Gujarat, India
> >>> >> http://www.jsptube.com

------------------------------------------------------------------------------
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.