Can't integrate my GoogleAppEngine(GAE/J) app with JPA (DataNucleus)

[Juan Manuel via StackOverflow]

I'm having problems running a Google App Engine app (GAE/J) trying to integrate with JPA but I can't make it work. I followed the simple steps of google official tutorial (http://code.google.com/appengine/docs/java/datastore/jpa/overview.html). I setted up the persistence.xml file in the right place, downloaded the JAR from the SDK and added to my project as external JARs (using Eclipse SDK). I'm currently not using Maven so i'm doing it manually.

When I run the GAE application the following WARNINGs, ERRORs and Exceptions appear on my Console:

Jan 27, 2011 3:47:11 PM com.google.apphosting.utils.jetty.JettyLogger info
        INFO: Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
        Jan 27, 2011 3:47:11 PM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
        INFO: Successfully processed /home/xxx/project/war/WEB-INF/appengine-web.xml
        Jan 27, 2011 3:47:11 PM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
        INFO: Successfully processed /home/xxx/project/war/WEB-INF/web.xml
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.natures" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.builders" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.markers" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.markers" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        [etc...]
        WARNING: Extension Point "org.eclipse.core.runtime.contentTypes" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.runtime.preferences" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.runtime.preferences" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.core.resources" but it cannot be resolved.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.core.runtime" but it cannot be resolved.
        Jan 27, 2011 3:47:28 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.text" but it cannot be resolved.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.natures" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.builders" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.markers" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.markers" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.resources.markers" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
       [etc...]
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry registerExtensions
        WARNING: Extension Point "org.eclipse.core.runtime.preferences" not registered, but plugin "org.eclipse.jdt.core" defined in file:/home/xxx/project/war/WEB-INF/lib/core-3.1.1.jar refers to it.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.core.resources" but it cannot be resolved.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.core.runtime" but it cannot be resolved.
        Jan 27, 2011 3:47:30 PM org.datanucleus.plugin.NonManagedPluginRegistry resolveConstraints
        SEVERE: Bundle "org.eclipse.jdt.core" requires "org.eclipse.text" but it cannot be resolved.
Jan 27, 2011 3:47:32 PM org.datanucleus.metadata.MetaDataManager initialiseFileMetaDataForUse
        SEVERE: Found Meta-Data for class escool.model.Person but this class is not enhanced!! Please enhance the class before running DataNucleus.
        org.datanucleus.exceptions.NucleusUserException: Found Meta-Data for class escool.model.Person but this class is not enhanced!! Please enhance the class before running DataNucleus.
            at org.datanucleus.metadata.MetaDataManager.initialiseClassMetaData(MetaDataManager.java:2225)
            at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaData(MetaDataManager.java:2176)
            at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaDataForUse(MetaDataManager.java:881)
            at org.datanucleus.metadata.MetaDataManager.loadPersistenceUnit(MetaDataManager.java:794)
            at org.datanucleus.jpa.EntityManagerFactoryImpl.initialisePMF(EntityManagerFactoryImpl.java:488)
            at org.datanucleus.jpa.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:355)
            at org.datanucleus.store.appengine.jpa.DatastoreEntityManagerFactory.<init>(DatastoreEntityManagerFactory.java:63)
            at org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider.createEntityManagerFactory(DatastorePersistenceProvider.java:35)
            at javax.persistence.Persistence.createFactory(Persistence.java:172)
            at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:112)
            at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:66)
            at escool.controllers.EMF.<clinit>(EMF.java:8)
            at escool.controllers.HomeController.<init>(HomeController.java:21)
            at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
            at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
            at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
            at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance_(Runtime.java:112)
            at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance(Runtime.java:120)
            at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:126)
            at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:72)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$3.run(AbstractAutowireCapableBeanFactory.java:943)
            at java.security.AccessController.doPrivileged(Native Method)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:941)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:901)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
            at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
            at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
            at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
            at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
            [etc...]
            at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:306)
            at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
            at javax.servlet.GenericServlet.init(GenericServlet.java:212)
            at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:440)
            at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:263)
            at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
            at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
            at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
            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 org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
            at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
            at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
            at org.mortbay.jetty.Server.doStart(Server.java:224)
            at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
            at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:185)
            at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:149)
            at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:219)
            at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:164)
            at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:48)
            at com.google.appengine.tools.development.DevAppServerMain.<init>(DevAppServerMain.java:113)
            at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:89)

Jan 27, 2011 3:47:32 PM org.springframework.web.servlet.FrameworkServlet initServletBean
        SEVERE: Context initialization failed
        org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController' defined in file [/home/jamoros/laburo/escool/war/WEB-INF/classes/escool/controllers/HomeController.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [escool.controllers.HomeController]: Constructor threw exception; nested exception is java.lang.ExceptionInInitializerError
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:955)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:901)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
            at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
            at [etc...] at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
                at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:185)
                at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:149)
                at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:219)
                at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:164)
                at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:48)
                at com.google.appengine.tools.development.DevAppServerMain.<init>(DevAppServerMain.java:113)
                at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:89)
            Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [escool.controllers.HomeController]: Constructor threw exception; nested exception is java.lang.ExceptionInInitializerError
                at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:141)
                at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:72)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$3.run(AbstractAutowireCapableBeanFactory.java:943)
                at java.security.AccessController.doPrivileged(Native Method)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:941)
                ... 37 more
            Caused by: java.lang.ExceptionInInitializerError
                at escool.controllers.HomeController.<init>(HomeController.java:21)
                at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
                at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
                at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
                at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
                at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance_(Runtime.java:112)
                at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance(Runtime.java:120)
                at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:126)
                ... 41 more
            Caused by: javax.persistence.PersistenceException: Provider error. Provider: org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider
                at javax.persistence.Persistence.createFactory(Persistence.java:176)
                at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:112)
                at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:66)
                at escool.controllers.EMF.<clinit>(EMF.java:8)
                ... 49 more
            Caused by: org.datanucleus.exceptions.NucleusUserException: Errors were encountered when initialising the specified MetaData. See the nested exceptions for details
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaDataForUse(MetaDataManager.java:892)
                at org.datanucleus.metadata.MetaDataManager.loadPersistenceUnit(MetaDataManager.java:794)
                at org.datanucleus.jpa.EntityManagerFactoryImpl.initialisePMF(EntityManagerFactoryImpl.java:488)
                at org.datanucleus.jpa.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:355)
                at org.datanucleus.store.appengine.jpa.DatastoreEntityManagerFactory.<init>(DatastoreEntityManagerFactory.java:63)
                at org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider.createEntityManagerFactory(DatastorePersistenceProvider.java:35)
                at javax.persistence.Persistence.createFactory(Persistence.java:172)
                ... 52 more
            Caused by: org.datanucleus.exceptions.NucleusUserException: Found Meta-Data for class escool.model.Person but this class is not enhanced!! Please enhance the class before running DataNucleus.
                at org.datanucleus.metadata.MetaDataManager.initialiseClassMetaData(MetaDataManager.java:2225)
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaData(MetaDataManager.java:2176)
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaDataForUse(MetaDataManager.java:881)
                ... 58 more
Jan 27, 2011 3:47:32 PM com.google.appengine.tools.development.ApiProxyLocalImpl log
SEVERE: javax.servlet.ServletContext log: unavailable
            org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController' defined in file [/home/jamoros/laburo/escool/war/WEB-INF/classes/escool/controllers/HomeController.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [escool.controllers.HomeController]: Constructor threw exception; nested exception is java.lang.ExceptionInInitializerError
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:955)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:901)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
                at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
                at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
                at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
                at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
                at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:563)
                at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:872)
                at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:423)
                at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442)
                at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)
                at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:339)
                at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:306)
                at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
                at javax.servlet.GenericServlet.init(GenericServlet.java:212)
                at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:440)
                at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:263)
                at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
                at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
                at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
                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 org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
                at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
                at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
                at org.mortbay.jetty.Server.doStart(Server.java:224)
                at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
                at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:185)
                at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:149)
                at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:219)
                at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:164)
                at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:48)
                at com.google.appengine.tools.development.DevAppServerMain.<init>(DevAppServerMain.java:113)
                at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:89)
            Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [escool.controllers.HomeController]: Constructor threw exception; nested exception is java.lang.ExceptionInInitializerError
                at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:141)
                at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:72)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$3.run(AbstractAutowireCapableBeanFactory.java:943)
                at java.security.AccessController.doPrivileged(Native Method)
                at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:941)
                ... 37 more
            Caused by: java.lang.ExceptionInInitializerError
                at escool.controllers.HomeController.<init>(HomeController.java:21)
                at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
                at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
                at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
                at java.lang.reflect.Constructor.newInstance(Constructor.java:532)
                at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance_(Runtime.java:112)
                at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance(Runtime.java:120)
                at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:126)
                ... 41 more
            Caused by: javax.persistence.PersistenceException: Provider error. Provider: org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider
                at javax.persistence.Persistence.createFactory(Persistence.java:176)
                at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:112)
                at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:66)
                at escool.controllers.EMF.<clinit>(EMF.java:8)
                ... 49 more
            Caused by: org.datanucleus.exceptions.NucleusUserException: Errors were encountered when initialising the specified MetaData. See the nested exceptions for details
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaDataForUse(MetaDataManager.java:892)
                at org.datanucleus.metadata.MetaDataManager.loadPersistenceUnit(MetaDataManager.java:794)
                at org.datanucleus.jpa.EntityManagerFactoryImpl.initialisePMF(EntityManagerFactoryImpl.java:488)
                at org.datanucleus.jpa.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:355)
                at org.datanucleus.store.appengine.jpa.DatastoreEntityManagerFactory.<init>(DatastoreEntityManagerFactory.java:63)
                at org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider.createEntityManagerFactory(DatastorePersistenceProvider.java:35)
                at javax.persistence.Persistence.createFactory(Persistence.java:172)
                ... 52 more
            Caused by: org.datanucleus.exceptions.NucleusUserException: Found Meta-Data for class escool.model.Person but this class is not enhanced!! Please enhance the class before running DataNucleus.
                at org.datanucleus.metadata.MetaDataManager.initialiseClassMetaData(MetaDataManager.java:2225)
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaData(MetaDataManager.java:2176)
                at org.datanucleus.metadata.MetaDataManager.initialiseFileMetaDataForUse(MetaDataManager.java:881)
                ... 58 more

Jan 27, 2011 3:47:32 PM com.google.appengine.tools.development.DevAppServerImpl start
INFO: The server is running at http://localhost:8888/

After this the app starts, but the JPA example that i have doesn't work...

What i'm doing wrong? What is this error? Do I need to configure anything else? Download a plugin ? Any idea... Any happy tutorial ?

Thanx!

Please DO NOT REPLY directly to this email but go to StackOverflow:
http://stackoverflow.com/questions/4818960/cant-integrate-my-googleappenginegae-j-app-with-jpa-datanucleus

[DataNucleus via StackOverflow]

Which bit about the message "Found Meta-Data for class escool.model.Person but this class is not enhanced!! Please enhance the class before running DataNucleus." is confusing ? Perhaps just enhance your class as requested.

Please DO NOT REPLY directly to this email but go to StackOverflow:

http://stackoverflow.com/questions/4818960/cant-integrate-my-googleappenginegae-j-app-with-jpa-datanucleus/4819328#4819328