Problems with GAE 1.7 JSF 2 deployment

Question

I followed this guide to make a JSF 2.1 project and deploy it to Google App Engine:

https://sites.google.com/a/wildstartech.com/adventures-in-java/Java-Platform-Enterprise-Edition/JavaServer-Faces/javaserver-faces-21/configuring-javaserver-faces-21-to-run-on-the-google-app-engine-using-eclipse

I works perfectly when I run it locally, but when I try to deploy the app at GAE, the following error occurs:

Uncaught exception from servlet java.lang.UnsupportedClassVersionError: com/sun/faces/config/WebConfiguration at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:163) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548) at org.mortbay.jetty.servlet.Context.startContext(Context.java:136) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.createHandler(AppVersionHandlerMap.java:202) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.getHandler(AppVersionHandlerMap.java:171) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:123) at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:477) at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449) at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455) at com.google.tracing.TraceContext.runInContext(TraceContext.java:695) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325) at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453) at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251) at java.lang.Thread.run(Thread.java:679)

What is happening? Im thinking about this new 1.7 JDK being responsible for it. When running locally, I need the to use "-XX:-UseSplitVerifier" to build the project correctly. Maybe GAE JDK is building it with other specs and causing this. I really Dunno.

The main question is: How do I solve this?

Answer 1

Quoting from documentation here

The Java Runtime Environment

App Engine runs Java applications using the Java 6 virtual machine (JVM). The App Engine SDK supports Java 5 and later, and the Java 6 JVM can use classes compiled with any version of the Java compiler up to Java 6.

So yes, the JDK 1.7 version is problem. Compile your project in 1.6 and you should be fine!