First, I want to say that I'm really impressed with Lift. It's a pleasure to work with (now that I've figured it out) and it keeps getting better.
I'm working on a Lift project that runs on Google App Engine. After an extended period of development on a local dev server, I uploaded my app and was surprised to discover it didn't work in the App Engine environment anymore. In the logs, I discovered that every request resulted in a HTTP 500 error. The root cause appeared to be a ClassNotFoundException thrown by com.google.apphosting.runtime.security.UserClassLoader while deserializing a net.liftweb.http.SessionToServletBridge. (Or possibly some object that contains a SessionToServletBridge?) I found an entry in the Google App Engine issue tracker noting problems with the deserialization of certain objects from a Session: http://code.google.com/p/googleappengine/issues/detail?id=1290 Some of the comments suggest that these objects are running afoul of App Engine's JRE White List: http://code.google.com/appengine/docs/java/jrewhitelist.html But I looked at the source for SessionToServletBridge and did not see any forbidden classes in the imports, so I'm not sure if that's the problem in this case. I was able get my app working again by reverting from the snapshot to version 1.1-M4, so presumably, the change that's causing the problem was introduced after the M4 milestone. I don't know if compatibility with App Engine is a priority for the Lift team, but if this doesn't get fixed, I face an ugly choice between remaining frozen at 1.1-M4 as Lift development moves forward, or migrating away from App Engine to another cloud solution. Is there anything I can do to assist the diagnosis/resolution of this issue? Thanks, Mark Here's the stack trace: javax.servlet.ServletException: java.lang.RuntimeException: java.lang.ClassNotFoundException: net.liftweb.http.SessionToServletBridge at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle (AppVersionHandlerMap.java:239) at org.mortbay.jetty.handler.HandlerWrapper.handle (HandlerWrapper.java:139) at org.mortbay.jetty.Server.handle(Server.java:313) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java: 506) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete (HttpConnection.java:830) at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable (RpcRequestParser.java:76) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest (JettyServletEngineAdapter.java:139) at com.google.apphosting.runtime.JavaRuntime.handleRequest (JavaRuntime.java:235) at com.google.apphosting.base.RuntimePb$EvaluationRuntime $6.handleBlockingRequest(RuntimePb.java:4823) at com.google.apphosting.base.RuntimePb$EvaluationRuntime $6.handleBlockingRequest(RuntimePb.java:4821) at com.google.net.rpc.impl.BlockingApplicationHandler.handleRequest (BlockingApplicationHandler.java:24) at com.google.net.rpc.impl.RpcUtil.runRpcInApplication(RpcUtil.java: 359) at com.google.net.rpc.impl.Server$2.run(Server.java:820) at com.google.tracing.LocalTraceSpanRunnable.run (LocalTraceSpanRunnable.java:56) at com.google.tracing.LocalTraceSpanBuilder.internalContinueSpan (LocalTraceSpanBuilder.java:516) at com.google.net.rpc.impl.Server.startRpc(Server.java:775) at com.google.net.rpc.impl.Server.processRequest(Server.java:348) at com.google.net.rpc.impl.ServerConnection.messageReceived (ServerConnection.java:436) at com.google.net.rpc.impl.RpcConnection.parseMessages (RpcConnection.java:319) at com.google.net.rpc.impl.RpcConnection.dataReceived (RpcConnection.java:290) at com.google.net.async.Connection.handleReadEvent(Connection.java: 428) at com.google.net.async.EventDispatcher.processNetworkEvents (EventDispatcher.java:762) at com.google.net.async.EventDispatcher.internalLoop (EventDispatcher.java:207) at com.google.net.async.EventDispatcher.loop(EventDispatcher.java: 101) at com.google.net.rpc.RpcService.runUntilServerShutdown (RpcService.java:251) at com.google.apphosting.runtime.JavaRuntime$RpcRunnable.run (JavaRuntime.java:374) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: net.liftweb.http.SessionToServletBridge at com.google.apphosting.runtime.jetty.SessionManager.deserialize (SessionManager.java:362) at com.google.apphosting.runtime.jetty.SessionManager.loadSession (SessionManager.java:280) at com.google.apphosting.runtime.jetty.SessionManager.getSession (SessionManager.java:255) at org.mortbay.jetty.servlet.AbstractSessionManager.getHttpSession (AbstractSessionManager.java:237) at org.mortbay.jetty.Request.getSession(Request.java:998) at org.mortbay.jetty.servlet.SessionHandler.handle (SessionHandler.java:192) at org.mortbay.jetty.handler.ContextHandler.handle (ContextHandler.java:712) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java: 405) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle (AppVersionHandlerMap.java:237) ... 27 more Caused by: java.lang.ClassNotFoundException: net.liftweb.http.SessionToServletBridge at com.google.apphosting.runtime.security.UserClassLoader$1.run (UserClassLoader.java:352) at com.google.apphosting.runtime.security.UserClassLoader$1.run (UserClassLoader.java:347) at java.security.AccessController.doPrivileged(Native Method) at com.google.apphosting.runtime.security.UserClassLoader.findClass (UserClassLoader.java:347) at java.lang.ClassLoader.loadClass(Unknown Source) at com.google.apphosting.runtime.security.UserClassLoader.loadClassImpl (UserClassLoader.java:434) at com.google.apphosting.runtime.security.UserClassLoader.loadClass (UserClassLoader.java:380) at java.lang.ClassLoader.loadClass(Unknown Source) at com.google.apphosting.runtime.jetty.SessionManager $DelegatingObjectInputStream.resolveClass(SessionManager.java:415) at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source) at java.io.ObjectInputStream.readClassDesc(Unknown Source) at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) at java.io.ObjectInputStream.readObject0(Unknown Source) at java.io.ObjectInputStream.readObject(Unknown Source) at java.util.HashMap.readObject(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at java.io.ObjectStreamClass.invokeReadObject(Unknown Source) at java.io.ObjectInputStream.readSerialData(Unknown Source) at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) at java.io.ObjectInputStream.readObject0(Unknown Source) at java.io.ObjectInputStream.defaultReadFields(Unknown Source) at java.io.ObjectInputStream.readSerialData(Unknown Source) at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) at java.io.ObjectInputStream.readObject0(Unknown Source) at java.io.ObjectInputStream.readObject(Unknown Source) at com.google.apphosting.runtime.jetty.SessionManager.deserialize (SessionManager.java:358) ... 35 more --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Lift" group. To post to this group, send email to liftweb@googlegroups.com To unsubscribe from this group, send email to liftweb+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/liftweb?hl=en -~----------~----~----~----~------~----~------~--~---
