GWT and OpenJPA not working together

[roman]

Hi,
I'm trying to implement a UserManagement based on GoogleWebToolkit
(Adding, deleting, assigning privileged; nothing special there). The
GWT-module is using a serparate persistence module, which I included
as a jar-file and which is based on OpenJPA.

The persistence layer is working fine as long is I run it standalone.
But when I wire it to my GWT project, I can't create the
EntityManagerFactory any more. I get a NullPointerException in one of
the OpenJPA classes, which I think is because that Google App Engine
replaced the default java.lang.ClassLoader.

Is it a bad idea to use OpenJPA with GWT? Is there anything to
consider when combining these libraries?

For better understanding find the source code attached.
Any help would be greatly appreciated.
thx, roman

The server is running at http://localhost:8888/
[WARN] Error for /usermgmtui/userInformation
java.lang.ExceptionInInitializerError
at org.apache.openjpa.kernel.Bootstrap.invokeFactory(Bootstrap.java:
116)
at
org.apache.openjpa.kernel.Bootstrap.getBrokerFactory(Bootstrap.java:
96)
at
org.apache.openjpa.persistence.OpenJPAPersistence.getEntityManagerFactory(OpenJPAPersistence.java:
92)
at
com.mycompany.commons.jpa.JpaUserManagement.<init>(JpaUserManagement.java:
64)
at
com.mycompany.commons.UserManagementImpl.setDatasoure(UserManagementImpl.java:
71)
at
com.mycompany.ui.server.UserInformationServiceImpl.<init>(UserInformationServiceImpl.java:
36)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown
Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at
org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:
428)
at
org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:
339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:
487)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1166)
at
com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:
35)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:
58)
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
com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:
122)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:
94)
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.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:
70)
at
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
152)
at com.google.appengine.tools.development.JettyContainerService
$ApiProxyHandler.handle(JettyContainerService.java:351)
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.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at
org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
409)
at org.mortbay.thread.QueuedThreadPool
$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.reflect.UndeclaredThrowableException
at $Proxy29.recordAppClassLoader(Unknown Source)
at
com.google.appengine.tools.development.agent.runtime.Runtime.recordClassLoader(Runtime.java:
47)
at
org.apache.openjpa.lib.util.MultiClassLoader.<init>(MultiClassLoader.java:
60)
at org.apache.openjpa.lib.util.J2DoPrivHelper
$47.run(J2DoPrivHelper.java:1011)
at org.apache.openjpa.lib.util.J2DoPrivHelper
$47.run(J2DoPrivHelper.java:1009)
at java.security.AccessController.doPrivileged(Native Method)
at
org.apache.openjpa.lib.conf.ProductDerivations.<clinit>(ProductDerivations.java:
59)
... 44 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.apphosting.utils.clearcast.ClearCast$CasterImpl
$ProxyHandler.invoke(ClearCast.java:411)
... 51 more
Caused by: java.lang.NullPointerException
at
org.apache.openjpa.lib.util.MultiClassLoader.hashCode(MultiClassLoader.java:
277)
at java.util.WeakHashMap.put(Unknown Source)
at
com.google.appengine.tools.development.agent.impl.AgentImpl.recordAppClassLoader(AgentImpl.java:
34)
... 56 more
[WARN] Nested in java.lang.ExceptionInInitializerError:
java.lang.reflect.UndeclaredThrowableException
at $Proxy29.recordAppClassLoader(Unknown Source)
at
com.google.appengine.tools.development.agent.runtime.Runtime.recordClassLoader(Runtime.java:
47)
at
org.apache.openjpa.lib.util.MultiClassLoader.<init>(MultiClassLoader.java:
60)
at org.apache.openjpa.lib.util.J2DoPrivHelper
$47.run(J2DoPrivHelper.java:1011)
at org.apache.openjpa.lib.util.J2DoPrivHelper
$47.run(J2DoPrivHelper.java:1009)
at java.security.AccessController.doPrivileged(Native Method)
at
org.apache.openjpa.lib.conf.ProductDerivations.<clinit>(ProductDerivations.java:
59)
at org.apache.openjpa.kernel.Bootstrap.invokeFactory(Bootstrap.java:
116)
at
org.apache.openjpa.kernel.Bootstrap.getBrokerFactory(Bootstrap.java:
96)
at
org.apache.openjpa.persistence.OpenJPAPersistence.getEntityManagerFactory(OpenJPAPersistence.java:
92)
at
com.mycompany.commons.jpa.JpaUserManagement.<init>(JpaUserManagement.java:
64)
at
com.mycompany.commons.UserManagementImpl.setDatasoure(UserManagementImpl.java:
71)
at
com.mycompany.ui.server.UserInformationServiceImpl.<init>(UserInformationServiceImpl.java:
36)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown
Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at
org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:
428)
at
org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:
339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:
487)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1166)
at
com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:
35)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:
58)
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
com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:
122)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:
94)
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.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:
70)
at
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
152)
at com.google.appengine.tools.development.JettyContainerService
$ApiProxyHandler.handle(JettyContainerService.java:351)
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.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at
org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
409)
at org.mortbay.thread.QueuedThreadPool
$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.apphosting.utils.clearcast.ClearCast$CasterImpl
$ProxyHandler.invoke(ClearCast.java:411)
... 51 more
Caused by: java.lang.NullPointerException
at
org.apache.openjpa.lib.util.MultiClassLoader.hashCode(MultiClassLoader.java:
277)
at java.util.WeakHashMap.put(Unknown Source)
at
com.google.appengine.tools.development.agent.impl.AgentImpl.recordAppClassLoader(AgentImpl.java:
34)
... 56 more


java.lang.NoClassDefFoundError: Could not initialize class
org.apache.openjpa.lib.conf.ProductDerivations
at org.apache.openjpa.kernel.Bootstrap.invokeFactory(Bootstrap.java:
116)
at
org.apache.openjpa.kernel.Bootstrap.getBrokerFactory(Bootstrap.java:
96)
at
org.apache.openjpa.persistence.OpenJPAPersistence.getEntityManagerFactory(OpenJPAPersistence.java:
92)
at
com.mycompany.commons.commons.jpa.JpaUserManagement.<init>(JpaUserManagement.java:
64)
at
com.mycompany.commons.commons.UserManagementImpl.setDatasoure(UserManagementImpl.java:
71)
at
com.mycompany.commons.ui.server.UserInformationServiceImpl.<init>(UserInformationServiceImpl.java:
36)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown
Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at
org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:
428)
at
org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:
339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:
487)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1166)
at
com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:
35)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:
58)
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
com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:
122)
at org.mortbay.jetty.servlet.ServletHandler
$CachedChain.doFilter(ServletHandler.java:1157)
at
com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:
94)
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.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:
70)
at
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:
152)
at com.google.appengine.tools.development.JettyContainerService
$ApiProxyHandler.handle(JettyContainerService.java:351)
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.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at
org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
409)
at org.mortbay.thread.QueuedThreadPool
$PoolThread.run(QueuedThreadPool.java:582)

[Patrick Julien]

If you wan't to use JPA with AppEngine, you have to use the JPA that
comes with AppEngine which is based on datanucleus. See

http://code.google.com/appengine/docs/java/datastore/jpa/overview.html

for an overview

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>

[roman]

Thank you for your quick response.
I followed your advise and changed the underlying technology of my JPA
layer to DataNucleus.

But i ran into a different problem

log4j:WARN No appenders could be found for logger
(DataNucleus.Connection).
log4j:WARN Please initialize the log4j system properly.
[ERROR] javax.servlet.ServletContext log: unavailable
javax.persistence.PersistenceException: Provider error. Provider:
org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider
at javax.persistence.Persistence.createFactory(Persistence.java:176)
...

at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at
org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:
409)
at org.mortbay.thread.QueuedThreadPool
$PoolThread.run(QueuedThreadPool.java:582)

Caused by: javax.jdo.JDOFatalInternalException: Unexpected exception
caught.
NestedThrowables:
java.lang.reflect.InvocationTargetException
at
javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(JDOHelper.java:
1186)
at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:
803)
at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:
698)
...
Caused by: java.lang.NoClassDefFoundError: java.io.FileOutputStream is
a restricted class. Please see the Google App Engine developer's
guide for more details.
at
com.google.appengine.tools.development.agent.runtime.Runtime.reject(Runtime.java:
51)
at
org.apache.derby.impl.services.stream.SingleStream.PBmakeFileHPW(Unknown
Source)
at org.apache.derby.impl.services.stream.SingleStream.run(Unknown
Source)

Well I see that i probably have got an error in the configuration of
the DataStorePersistenceProvider. Unfortunately, I am not sure what
the error could be. Is there any way to get a more specific
description of what is causing the problem?

cheers, roman

On 27 Mai, 15:28, Patrick Julien <pjul...@gmail.com> wrote:
> If you wan't to use JPA with AppEngine, you have to use the JPA that
> comes with AppEngine which is based on datanucleus.  See
>
> http://code.google.com/appengine/docs/java/datastore/jpa/overview.html
>
> for an overview
>
>
>
>
>
>
>
> On Fri, May 27, 2011 at 5:56 AM, roman <roman.za...@gmail.com> wrote:
> > Hi,
> > I'm trying to implement a UserManagement based on GoogleWebToolkit
> > (Adding, deleting, assigning privileged; nothing special there). The
> >GWT-module is using a serparate persistence module, which I included
> > as a jar-file and which is based onOpenJPA.
>
> > The persistence layer is working fine as long is I run it standalone.

> > But when I wire it to myGWTproject, I can't create the

> > EntityManagerFactory any more. I get a NullPointerException in one of

> > theOpenJPAclasses, which I think is because that Google App Engine
> > replaced the default java.lang.ClassLoader.
>
> > Is it a bad idea to useOpenJPAwithGWT? Is there anything to

> > consider when combining these libraries?
>
> > For better understanding find the source code attached.
> > Any help would be greatly appreciated.
> > thx, roman
>

> > The server is running athttp://localhost:8888/

> ...
>
> Erfahren Sie mehr »

[roman]

One more thing, that just came to my mind.
My solution also uses and is based on Apache James, which in return
has got an OpenJPA layer. That's why I did choose OpenJPA in the first
place.
So when you say that I have to use JPA layer of the appengine, hence
datanucleus, I really doubt that my James server will work as it
normally would. What are my chances of having a GWT frontend for a
user management that persists data into a Derby database; and a James
server that reads the data configured to work I need it to.
To make things even more challenging, it would be great to reuse
James' databaseconnection and use it in my user management.

cheers

> ...
>
> Erfahren Sie mehr »

[Patrick Julien]

I think that's specific enough:

"Caused by: java.lang.NoClassDefFoundError: java.io.FileOutputStream
is a restricted class. Please see the Google App Engine developer's
guide for more details."

[roman]

allright. your push made me look into it a little deeper :-)
My solution to the "NoClassDefFoundError: java.io.FileOutputStream is
a restricted class" is disabling the usage of Google's App engine
under Project - Properties | Google | App Engine | Use Google App
Engine --> uncheck

After that i got "ClassCastException:
org.datanucleus.store.rdbms.RDBMSManager cannot be cast to
org.datanucleus.store.appengine.DatastoreManager" which made me
banning the datanucleus-appengine-1.0.8.final.jar from the projects
classpath as well.
I have no clue if this is a good idea, but my code is running so far
and I am able to make calls to the Derby database.

Which brings me back to my other question:
Is it utterly impossible to have the persistence layer running with
OpenJPA along with a GWT frontend? As I fear Apache James is dependent
on its familiar JPA technology.

again, thanks for your advice. you helped me loads
alltogether I spent already a week on these issues, and I'm craving
for answers
cheers

> ...
>
> Erfahren Sie mehr »

[Patrick Julien]

OpenJPA works fine with GWT. Your issues have to do with the fact
you're running on AppEngine. I don't even see how it's possible you
got derby running on AppEngine unless you're using an all memory
database.

[roman]

Thats good news!
Well obviously I am doing something wrong. When i discovered that I
have to remove the appengine jar from my classpath - to avoid problem
with dataNucleus - yesterday, I also tried the same in my dev branch
with OpenJPA. I saw some other exception.
But now that I know it should work, i can continue investigating.

It's definitly a filebased instance of Derby DB. My connection string
points to "C:\bin\apache-james\..."
cheers

> ...
>
> Erfahren Sie mehr »