Re: KernelRegistry does not return a reference to Kernel + class loader issue

Tue, 21 Mar 2006 09:24:54 -0800 

A couple of possibly helpful or misleading hints :-)
-- I dont' think that putting anything in lib/endorsed will lead to joy :-) I think you need to put all the ojb related stuff in the repository and get it into the same classloader by putting dependencies to it in the same plan. 


-- I don't see that you are using web apps, but if you are you  
probably want to take all the jars out of WEB-INF/lib and put them in  
the repository and use plan dependencies instead: this won't be  
necessary in 1.1.



-- you might look in the spring module in trunk to see a similar way  
of fishing out the transaction manager to integrate in another  
framework.  I'm not sure this code actually works at the moment.



-- be aware that jndi only works on threads that have gone through a  
j2ee component.  If you are trying to e.g. look up the datasource in  
ojb from some startup thread such as a gbean constructor or doStart  
method, jndi won't work.  If you look up a datasource in jndi during  
a call from an ejb, and the datasource is declared as a resource-ref  
in your dd and plan, that should work.  If you need the datasource in  
a gbean you should use a gbean reference to the  
ManagedConnectionFactoryWrapper gbean and get the datasource by  
calling $getResource: see the system-datasource plan and the jdbc  
timers for an example.



--Something like what you are doing ought to work: jetspeed 2 which  
uses ojb seems to work fine in geronimo (after sufficient porting :-)


Hope this helps,

david jencks

On Mar 21, 2006, at 8:24 AM, Aaron Mulder wrote:


For the kernel problem, what kind of code is calling
Kernel.getSingleKernel?  When you say it returns null and you don't
get any exception on the server side, it makes it sound like a client
is calling Kernel.getSingleKernel, which we would not expect to work.
That method will probably only work within the server VM.  There is a
way to get a remote Kernel, but it's more complex (you can look at how
it's done in the deploy tool, for example).

So here's what looks like the key part of the class loading problem:

java.lang.NoClassDefFoundError: javax/management/ObjectName
       at

com..ojb.transaction.WebSphereCETransactionManagerFactory.getTransacti 
on

Manager(WebSphereCETransactionManagerFactory.java:48)
       at

org.apache.ojb.broker.core.PersistenceBrokerFactorySyncImpl.<init> 
(Unkno

wn Source)

Did you abbreviate that 2nd line?  I think that's an important one.
Something related to OJB cannot find the JMX classes...  But it
doesn't look like that's actually an OJB class since it starts with
"com." -- we need to figure out who's providing that class.  Maybe
com.xmeta?  Is that actually your code?

As far as classloaders go, it looks like CoreRepositoryFactory is
creating a new class, and then PersistenceBrokerFactoryFactory is
trying to create a class, and then PersistenceBrokerFactorySyncImpl is

trying to call  
WebSphereCETransactionManagerFactory.getTransactionManager

and that's got the wrong class loader.  So they key will be idenfiying
what CL is used at each step and where it goes wrong.

Also, how are OJB and xmeta packaged in your application?  Are they
included in WEB-INF/lib, for example, or in a JAR in the Geronimo
repository, or what?

Thanks,
    Aaron

On 3/21/06, Siraj Mohamed <[EMAIL PROTECTED]> wrote:

Thanks Aaron for a reply.


Let me explain what I am really doing. We have an EJB application  
(EAR)

which is running on WebSphere and I am currently migrating this into
WASCE.


This is the back end service called 'xmeta' which let user perform  
any

database activities through Apache OJB and EMF (Eclipse Modeling
Framework).  The xmeta EAR contains many EJBs with public interface
methods so that end user could use it to perform 'insert', 'delete',
'update' operations on the target database through ORM. The OJB
configuration is provided with a jar named ojb-conf.jar which has

information about data source reference, ORM mappings and a java  
class
which is used to get a TransactionManager of the application  
server. For

example, Apache provides

org.apache.ojb.broker.transaction.tm.JBossTransactionManagerFactory f 
or

Jboss and

org.apache.ojb.broker.transaction.tm.WebSphereTransactionManagerFacto 
ry

for Websphere. My intention is to write a java class
(WebSphereCETransactionManagerFactory) same as websphere and jboss to
get a reference of the TransactionManager so that I can specify this

class name in the OJB.properties (it is bundled in the ojb- 
conf.jar) and

the class name is specified with a key JTATransactionManagerClass= in
same the property file. My original mail refers this java class and I
just wanted to test my code. I ran this class through eclipse but
following code returns null.

kernel = KernelRegistry.getSingleKernel();


I do not get any exception in the server side and it just returns  
me a
null. That was my first problem and I am not sure why am I getting  
null.

Do I need any additional code to get a connection to the WASCE before
getting Kernel? My class path has the jndi.properties for WASCE.

This is my 2nd problem and it seems to be a class loader problem. I
could able to deploy my xmeta application (EAR) successfully on WASCE

and I also successfully created a data source with MySQL as back  
end. My

next step is to see whether I could talk to database through OJB by
invoking a method of a service of xmeta application (say
SandboxAdminService). I bundled my written java class in a jar and
copied it to the WASCE_HOME\lib\endorsed folder and also copied
ojb-conf.jar to the same folder. The ojb-conf.jar will be read by

SandboxAdminService EJB to get information such as data source  
name and

the java class name which is used to get a reference of the
TransactionManager and other ORM mappings.

At end, when I invoke client, I am getting following
NoClassDefFoundError:

17:00:17,861 INFO  [RepositoryPersistor] OJB Descriptor Repository:

jar:file:/C:/IBM/WebSphere/AppServerCommunityEdition/lib/endorsed/ 
ojb-co

nf.jar!/repository.xml
17:00:17,861 INFO  [RepositoryPersistor] Building repository from

:jar:file:/C:/IBM/WebSphere/AppServerCommunityEdition/lib/endorsed/ 
ojb-c

onf.jar!/repository.xml

17:00:18,268 INFO  [RepositoryPersistor] Read class descriptors  
took 407

ms
17:00:18,268 INFO  [RepositoryPersistor] OJB Descriptor Repository:

jar:file:/C:/IBM/WebSphere/AppServerCommunityEdition/lib/endorsed/ 
ojb-co

nf.jar!/repository.xml
17:00:18,268 INFO  [RepositoryPersistor] Building repository from

:jar:file:/C:/IBM/WebSphere/AppServerCommunityEdition/lib/endorsed/ 
ojb-c

onf.jar!/repository.xml

17:00:18,377 INFO  [RepositoryPersistor] Read connection  
repository took

109 ms
17:00:18,424 INFO  [PersistenceBrokerFactoryDefaultImpl] Create
PersistenceBroker instance pool, pool configuration was
{whenExhaustedAction=2, maxIdle=-1, maxActive=100, maxWait=2000,

removeAbandoned=false, numTestsPerEvictionRun=10,  
testWhileIdle=false,

minEvictableIdleTimeMillis=1000000, testOnReturn=false,
logAbandoned=false, removeAbandonedTimeout=300,
timeBetweenEvictionRunsMillis=-1, testOnBorrow=false}
17:00:18,424 INFO  [WebSphereCETransactionManagerFactory]
WebSphereCETransactionManagerFactory +++++++++ 1
17:00:18,424 WARN  [SystemExceptionInterceptor] SandboxAdminService
java.lang.NoClassDefFoundError: javax/management/ObjectName
        at

com..ojb.transaction.WebSphereCETransactionManagerFactory.getTransact 
ion

Manager(WebSphereCETransactionManagerFactory.java:48)
        at

org.apache.ojb.broker.core.PersistenceBrokerFactorySyncImpl.<init> 
(Unkno

wn Source)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0 
(Native

Method)
        at

sun.reflect.NativeConstructorAccessorImpl.newInstance 
(NativeConstructorA

ccessorImpl.java(Compiled Code))
        at

sun.reflect.DelegatingConstructorAccessorImpl.newInstance 
(DelegatingCons

tructorAccessorImpl.java(Compiled Code))
        at
java.lang.reflect.Constructor.newInstance(Constructor.java(Compiled
Code))
        at java.lang.Class.newInstance3(Class.java(Compiled Code))
        at java.lang.Class.newInstance(Class.java(Compiled Code))
        at org.apache.ojb.broker.util.ClassHelper.newInstance(Unknown
Source)
        at

org.apache.ojb.broker.core.PersistenceBrokerFactoryFactory.init 
(Unknown

Source)
        at

org.apache.ojb.broker.core.PersistenceBrokerFactoryFactory.<clinit> 
(Unkn

own Source)
        at

com.xmeta.persistence.orm.impl.ojb.JBossOjbPersistenceBrokerFactory.c 
rea

tePersistenceBroker(JBossOjbPersistenceBrokerFactory.java:47)
        at

com.xmeta.persistence.orm.impl.ojb.AbstractOjbPersistenceBrokerFactor 
y.c

reateBroker(AbstractOjbPersistenceBrokerFactory.java:50)
        at

com.xmeta.persistence.orm.impl.ojb.OjbObjectPersistence.getBroker 
(OjbObj

ectPersistence.java:72)
        at

com.xmeta.persistence.orm.impl.ojb.OjbPersistentEObjectPersistence.ge 
tBr

oker(OjbPersistentEObjectPersistence.java:162)
        at

com.xmeta.persistence.orm.impl.ojb.OjbPersistentEObjectPersistenceReg 
ist

ry.getBroker(OjbPersistentEObjectPersistenceRegistry.java:301)
        at

com.xmeta.persistence.orm.impl.ojb.OjbPersistentEObjectPersistenceReg 
ist

ry.loadPackageCache(OjbPersistentEObjectPersistenceRegistry.java:350)
        at

com.xmeta.persistence.orm.impl.ojb.OjbPersistentEObjectPersistenceReg 
ist

ry.initialize(OjbPersistentEObjectPersistenceRegistry.java:131)
        at

com.xmeta.persistence.orm.impl.ojb.OjbPersistentEObjectPersistence.in 
iti

alize(OjbPersistentEObjectPersistence.java:318)
        at

com.xmeta.persistence.impl.basic.BasicPersistence.initialize 
(BasicPersis

tence.java:369)
        at

com.xmeta.persistence.impl.basic.BasicPersistenceManager.initialize 
(Basi

cPersistenceManager.java:75)
        at

com.xmeta.repository.core.impl.DefaultSandboxAdmin.<init> 
(DefaultSandbox

Admin.java:124)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0 
(Native

Method)
        at

sun.reflect.NativeConstructorAccessorImpl.newInstance 
(NativeConstructorA

ccessorImpl.java(Compiled Code))
        at

sun.reflect.DelegatingConstructorAccessorImpl.newInstance 
(DelegatingCons

tructorAccessorImpl.java(Compiled Code))
        at
java.lang.reflect.Constructor.newInstance(Constructor.java(Compiled
Code))
        at java.lang.Class.newInstance3(Class.java(Compiled Code))
        at java.lang.Class.newInstance(Class.java(Compiled Code))
        at

com.xmeta.repository.core.CoreRepositoryFactory.createSandboxAdmin 
(CoreR

epositoryFactory.java:153)
        at

com.xmeta.service.repository.core.SandboxAdminServiceBean.<init> 
(Sandbox

AdminServiceBean.java:115)
        at

com.xmeta.service.repository.core.SandboxAdminServiceBean$ 
$FastClassByCG

LIB$$d9825d07.newInstance(<generated>)

        at net.sf.cglib.reflect.FastClass.newInstance 
(FastClass.java:91)

        at

org.openejb.EJBInstanceFactoryImpl.newInstance 
(EJBInstanceFactoryImpl.ja

va:76)
        at

org.openejb.sfsb.StatefulInstanceContextFactory.newInstance 
(StatefulInst

anceContextFactory.java:119)
        at

org.openejb.sfsb.StatefulInstanceFactory.createInstance 
(StatefulInstance

Factory.java:86)
        at

org.openejb.sfsb.StatefulInstanceInterceptor.getInstanceContext 
(Stateful

InstanceInterceptor.java:144)
        at

org.openejb.sfsb.StatefulInstanceInterceptor.invoke 
(StatefulInstanceInte

rceptor.java:92)
        at

org.openejb.transaction.ContainerPolicy$TxNotSupported.invoke 
(ContainerP

olicy.java:89)
        at

org.openejb.transaction.TransactionContextInterceptor.invoke 
(Transaction

ContextInterceptor.java:80)
        at

org.openejb.SystemExceptionInterceptor.invoke 
(SystemExceptionInterceptor

.java:82)
        at
org.openejb.GenericEJBContainer.invoke(GenericEJBContainer.java:238)
        at

org.openejb.server.ejbd.EjbRequestHandler.invoke 
(EjbRequestHandler.java:

297)
        at

org.openejb.server.ejbd.EjbRequestHandler.doEjbHome_CREATE 
(EjbRequestHan

dler.java:342)
        at

org.openejb.server.ejbd.EjbRequestHandler.processRequest 
(EjbRequestHandl

er.java:205)

        at org.openejb.server.ejbd.EjbDaemon.service 
(EjbDaemon.java:150)
        at org.openejb.server.ejbd.EjbServer.service 
(EjbServer.java:87)

        at

org.openejb.server.ejbd.EjbServer$$FastClassByCGLIB$ 
$d379d2ff.invoke(<ge

nerated>)
        at net.sf.cglib.reflect.FastMethod.invoke(FastMethod.java:53)
        at

org.apache.geronimo.gbean.runtime.FastMethodInvoker.invoke 
(FastMethodInv

oker.java:38)
        at

org.apache.geronimo.gbean.runtime.GBeanOperation.invoke 
(GBeanOperation.j

ava:118)
        at

org.apache.geronimo.gbean.runtime.GBeanInstance.invoke 
(GBeanInstance.jav

a:800)
        at

org.apache.geronimo.gbean.runtime.RawInvoker.invoke 
(RawInvoker.java:57)

        at

org.apache.geronimo.kernel.basic.RawOperationInvoker.invoke 
(RawOperation

Invoker.java:36)
        at

org.apache.geronimo.kernel.basic.ProxyMethodInterceptor.intercept 
(ProxyM

ethodInterceptor.java:96)
        at

org.activeio.xnet.ServerService$$EnhancerByCGLIB$$81781c7d.service 
(<gene

rated>)
        at org.activeio.xnet.ServicePool$2.run(ServicePool.java:67)
        at org.activeio.xnet.ServicePool$3.run(ServicePool.java:90)
        at

org.apache.geronimo.pool.ThreadPool$ContextClassLoaderRunnable.run 
(Threa

dPool.java:138)
        at
EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(Unknown
Source)
        at java.lang.Thread.run(Thread.java:570)



The exception is occurred at my newly written java class but the  
class

javax/management/ObjectName is bundled with mx4j-3.0.1.jar which is
available at WASCE_HOME\lib. It seems that WASCE class loader is not

visible to either to EJB or 'endrosed' folder? I am not sure I was  
right

that LIB folder is parent class loader and the endorsed is a child of
lib?

Please appreciate your help to resolve this problem.

FYI: I have bundled all dependency Jars into EAR and this is my
deployment plan

<?xml version="1.0" encoding="UTF-8"?>

<application
     xmlns="http://geronimo.apache.org/xml/ns/j2ee/application";
     configId="RXMeta"
   parentId="geronimo/j2ee-server/1.0/car"



</application>

This is my openejb-jar.xml

<?xml version="1.0"?>

<openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar";
configId="ejb-RXMeta"
parentId="geronimo/j2ee-server/1.0/car">

<enterprise-beans>
      <session>
         <ejb-name>ImportService</ejb-name>
         <jndi-name>ImportService</jndi-name>

      </session>

      <session>
         <ejb-name>SandboxService</ejb-name>
         <jndi-name>SandboxService</jndi-name>

         <resource-ref>
            <ref-name>xmeta_defaultDS</ref-name>
            <resource-link>ASB</resource-link>
         </resource-ref>

      </session>

      <session>
         <ejb-name>ObjectDifferencingService</ejb-name>
         <jndi-name>ObjectDifferencingService</jndi-name>


      </session>

      <session>
         <ejb-name>GlobalSessionService</ejb-name>
         <jndi-name>GlobalSessionService</jndi-name>

      </session>

      <session>
         <ejb-name>DSImpactAnalysisService</ejb-name>
         <jndi-name>DSImpactAnalysisService</jndi-name>
      </session>

      <session>
         <ejb-name>OperationalRepositoryService</ejb-name>
         <jndi-name>OperationalRepositoryService</jndi-name>

         <resource-ref>
            <ref-name>xmeta_defaultDS</ref-name>
            <resource-link>ASB</resource-link>
         </resource-ref>

      </session>
      <session>
         <ejb-name>ExportService</ejb-name>
         <jndi-name>ExportService</jndi-name>

      </session>
      <session>
         <ejb-name>ImpactAnalysisService</ejb-name>
         <jndi-name>ImpactAnalysisService</jndi-name>

      </session>
      <session>
         <ejb-name>MetabrokerAdminService</ejb-name>
         <jndi-name>MetabrokerAdminService</jndi-name>

      </session>
      <session>
         <ejb-name>ObjectMergeService</ejb-name>
         <jndi-name>ObjectMergeService</jndi-name>

      </session>
      <session>
         <ejb-name>ImportDecodeService</ejb-name>
         <jndi-name>ImportDecodeService</jndi-name>

      </session>
      <session>
         <ejb-name>OperationalRepositoryAdminService</ejb-name>
         <jndi-name>OperationalRepositoryAdminService</jndi-name>

         <resource-ref>
            <ref-name>xmeta_defaultDS</ref-name>
            <resource-link>ASB</resource-link>
         </resource-ref>

      </session>
      <session>
         <ejb-name>StaticDataLineageService</ejb-name>
         <jndi-name>StaticDataLineageService</jndi-name>

      </session>
      <session>
         <ejb-name>SandboxAdminService</ejb-name>
         <jndi-name>SandboxAdminService</jndi-name>

         <resource-ref>
            <ref-name>xmeta_defaultDS</ref-name>
            <resource-link>ASB</resource-link>
         </resource-ref>


      </session>

</enterprise-beans>

</openejb-jar>


Thanks & Regards,
Siraj













-----Original Message-----

From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of  
Aaron

Mulder
Sent: Monday, March 20, 2006 10:10 PM
To: [email protected]
Subject: Re: KernelRegistry does not return a reference to Kernel


If you're working on application code, is there a reason you're  
trying

to use a TransactionManager instead of getting a UserTransaction from
JNDI?  If you're writing a GBean you should have the
TransactionManager injected (configured as a reference) instead of
looking it up.

In any case, it would generally help if you post the stack trace and
double-check to be absolutely sure that it's definitely the
getSingleKernel method that's returning null and not some surrounding
code.  In this particular case I'm not sure how much a stack trace
will help since I'm not sure what SVN revision of Geronimo the WASCE
code is based on and what IBM might have changed, but it's certainly
the case that you don't have much of a chance of a better diagnosis
*without* the stack trace.  :)

Thanks,
    Aaron

On 3/20/06, Siraj Mohamed <[EMAIL PROTECTED]> wrote:




Hi All,




I am using WASCE 1.0.0.1 version and I am trying to get a  
reference to

the

TransactionManger from a Java class. This is the segment of my java

class.




TransactionManager tm = null;

try

{

            ObjectName TM_NAME = new




ObjectName 
("geronimo.server:J2EEApplication=null,J2EEModule=geronimo/j2e
e-server/1.0/ 
car,J2EEServer=geronimo,j2eeType=TransactionManager,name=Tr

ansactionManager");






            Kernel kernel = KernelRegistry.getSingleKernel();

            tm =
(TransactionManager)kernel.getProxyManager().createProxy(TM_NAME,

            TransactionManager.class);



}catch (Exception e)

{

            throw new
TransactionManagerFactoryException(e.getMessage());

}



This code does not work for me and I get a null return value when

trying to

get the Kernel (KernelRegistry.getSingleKernel()).



Am I missing some thing else? My WASCE application server is running

up and

down.



Please help me if any one knows the solution.



Thanks and Regards,

Siraj


























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