Classloader problem in MBean

[ju_du]

Hi,

this posting is not specific to JBoss, but I don't know any other newsgroup with as much as knowladge about JMX. This question regards to the JMX book by juha.

I write my own NetworkApp as in Chapter 7 (It starts the MBeanServer and creates a MLet MBean). The MLet MBean loads my MBean. This MBean tries to get the InitialContextFactory of an IBM WebSphere.

Hashtable table = new Hashtable();
table.put(Context.INITIAL_CONTEXT_FACTORY, "com.ibm.websphere.naming.WsnInitialContextFactory");
table.put(Context.PROVIDER_URL,"iiop://localhost:900");
Context ctx = new InitialContext(table);

But I get a ClassNotFoundException (see below). If I try:

Class.forName("com.ibm.websphere.naming.WsnInitialContextFactory");

it seems that the MBean find the ContextFactory. In my opinion the problem arises because of the use of the Classloader.

Any suggestions?

Thanks a lot,
Juergen




java.lang.ClassNotFoundException: com.ibm.websphere.naming.WsnInitialContextFactory

at java.net.URLClassLoader$1.run(URLClassLoader.java:200)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:188)

at java.lang.ClassLoader.loadClass(ClassLoader.java:299)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:286)

at java.lang.ClassLoader.loadClass(ClassLoader.java:255)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:315)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:195)

at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.java:45)

at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:652)

at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:246)

at javax.naming.InitialContext.init(InitialContext.java:222)

at javax.naming.InitialContext.(InitialContext.java:198)

at com.entory.base.common.svcloc.JNDIAccessor.connect(JNDIAccessor.java:117)

at com.entory.base.common.svcloc.JNDIAccessor.(JNDIAccessor.java:89)

at com.entory.base.common.svcloc.ServiceLocator.openConnectionIfNecessary(ServiceLocator.java:573)

at com.entory.base.common.svcloc.ServiceLocator.createEJBHome(ServiceLocator.java:367)

at com.entory.upm.client.common.ServiceLocatorClient.getAdmin(ServiceLocatorClient.java:87)

at com.entory.upm.client.admin.AdminCF.(AdminCF.java:67)

at com.entory.upm.imprt.paisy.InitialLine.insert(InitialLine.java:80)

at com.entory.upm.imprt.paisy.FileGuard.readFromFile(FileGuard.java:41)

at com.entory.upm.imprt.paisy.PaisyImport.start(PaisyImport.java:36)

at java.lang.reflect.Method.invoke(Native Method)

at com.sun.jdmk.MetaDataImpl.invoke(MetaDataImpl.java:535)

at com.sun.jdmk.DefaultMBeanAccessor.invoke(DefaultMBeanAccessor.java:528)

at com.sun.jdmk.MBeanServerImpl.invoke(MBeanServerImpl.java:579)

at com.entory.upm.imprt.server.ImportServer.main(ImportServer.java:76)

[sgturner]

Consult Websphere docs to learn what classes you need to get a Context reference externally. Then make those classes available to the MBean.

[ju_du]

I put all required JAR-Files in to the MLet-Tag:



I mean that's problem with the URLClassloader.

Juergen

[marc.fleury]

This is probably a bug with the IBM implementation, it is known to be flaky. Try running your stuff in JBoss it should work as is as you describe. Also try using a service.xml file instead of this flaky MLet format.

The classloader stuff is tricky and really the base of the MX stuff. It is rock solid in there, the class visibility won't cause you problems,