Richard,
In thinking about this further, the situation seems worse that at
first glance: suppose I have a method on the proxy discussed below:
Object getSomething();
And suppose that the actual return type can be any of 50 types, each
from one of 50 different packages, all in the JDK (eg javax.management).
One wouldn't know at *compile* time that that there are 50 latent
runtime errors (NoClassDefFoundError).
The product is tested with (say) 10 types; the problem is corrected
for them. The customer is shipped a product that fails for the other
40 types.
What prevents such an ugly scenario?
What about future changes to the underlying code that returns still
more types that the intermediate module knows nothing about leading to
yet more runtime errors?
Lloyd
On Jun 16, 2009, at 2:58 PM, Lloyd Chambers wrote:
> Richard,
>
> Thank you.
>
> That does seem to be it: the interface used (J2EEServer) resides in
> the amx-j2ee module, which doesn't import javax.management. But it
> does have a dependency on amx-core, which both imports and exports
> javax.management (I checked the manifest).
>
> So even though the module implementing getSelf() uses
> javax.management and the calling code does also, and the proxy code
> does also, using that interface (J2EEServer) causes the problem.
>
> I guess that makes an explanation, but I still find it startling
> that built-in JDK classes can be hidden this way and that
> dependencies aren't really transitive.
>
> Lloyd
>
> On Jun 16, 2009, at 1:11 PM, Richard S. Hall wrote:
>
>> The last time this issue happened, it was because not all of the
>> bundles involved import javax.management...
>>
>> Check the dev_at_glassfish mailing list archives for the thread
>> "broken Felix classloader"...
>>
>> -> richard
>>
>> On 6/16/09 4:01 PM, Lloyd Chambers wrote:
>>>
>>> I forgot to mention: the manifest includes javax.management. So
>>> how can javax.management.ObjectName not be found?
>>>
>>> Import-Package:
>>> com.sun.enterprise.config.serverbeans;version="3.0",co
>>>
>>> m
>>> .sun.enterprise.deployment;version="3.0",com.sun.enterprise.deployme
>>>
>>> nt
>>> .io;version="3.0",com.sun.enterprise.deployment.util;version="3.0",
>>>
>>> javax
>>> .management,javax.management.j2ee;version="1.1",javax.naming,jav
>>>
>>> ax
>>> .rmi,org.glassfish.admin.amx.annotation;version="3.0",org.glassfish
>>> .admin
>>> .amx.base;version="3.0",org.glassfish.admin.amx.config;version=
>>>
>>> "3.0
>>> ",org.glassfish.admin.amx.core;version="3.0",org.glassfish.admin.
>>>
>>> amx
>>> .core.proxy;version="3.0",org.glassfish.admin.amx.impl.j2ee;versio
>>>
>>> n
>>> ="3.0",org.glassfish.admin.amx.impl.j2ee.loader;version="3.0",org.gl
>>>
>>> assfish
>>> .admin.amx.impl.mbean;version="3.0",org.glassfish.admin.amx.im
>>>
>>> pl
>>> .util;version="3.0",org.glassfish.admin.amx.intf.config;version="3.
>>>
>>> 0
>>> ",org.glassfish.admin.amx.j2ee;version="3.0",org.glassfish.admin.amx
>>> .util
>>> ;version="3.0",org.glassfish.admin.amx.util.jmx;version="3.0",or
>>>
>>> g
>>> .glassfish.api.amx;version="3.0",org.glassfish.internal.data;version
>>>
>>> =
>>> "3.0",org.jvnet.hk2.annotations;version="0.3",org.jvnet.hk2.componen
>>> t;version="0.3"
>>>
>>>
>>>
>>> On Jun 16, 2009, at 12:51 PM, Lloyd Chambers wrote:
>>>
>>>> I've run into a problem like this before and I don't know why
>>>> OSGI requires breaking the JDK. I forget the solution, but I'm
>>>> stuck until I find one.
>>>> ...
>>>>
>>>> Module amx-j2ee-impl has a dependency on module amx-core-impl,
>>>> and calls getSelf(J2EEServer.class). Method getSelf() is in a
>>>> superclass which is found in the amx-core-impl module. The
>>>> generated proxy uses a handler defined in the amx-core module.
>>>>
>>>> The calling code looks like this:
>>>>
>>>> import javax.management.ObjectName; <=== imports the problem class
>>>> ...
>>>> J2EEServer selfProxy = getSelf(J2EEServer.class); <== call
>>>> superclass method in another module
>>>> ObjectName test = selfProxy.objectName(); <==
>>>> ClassNotFoundException
>>>>
>>>> The proxy method objectName() returns a
>>>> javax.management.ObjectName, a standard class in the JDK.
>>>>
>>>> Yet, I get a NoClassDefFoundError. This seems like a bug to me,
>>>> and I don't know how to fix it.
>>>>
>>>>
>>>> SEVERE: Caused by: java.lang.NoClassDefFoundError: javax/
>>>> management/ObjectName
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at $Proxy107.objectName(Unknown Source)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org
>>>> .glassfish
>>>> .admin
>>>> .amx
>>>> .impl.j2ee.J2EEServerImpl.registerChildren(J2EEServerImpl.java:102)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org
>>>> .glassfish
>>>> .admin
>>>> .amx
>>>> .impl
>>>> .j2ee.DASJ2EEServerImpl.registerChildren(DASJ2EEServerImpl.java:68)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org
>>>> .glassfish
>>>> .admin
>>>> .amx.impl.mbean.AMXImplBase.postRegisterHook(AMXImplBase.java:1218)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org
>>>> .glassfish
>>>> .admin
>>>> .amx.impl.mbean.MBeanImplBase.postRegister(MBeanImplBase.java:440)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> com
>>>> .sun
>>>> .jmx
>>>> .interceptor
>>>> .DefaultMBeanServerInterceptor
>>>> .postRegisterInvoke(DefaultMBeanServerInterceptor.java:1035)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: ... 15 more
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: Caused by: java.lang.ClassNotFoundException:
>>>> javax.management.ObjectName
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org
>>>> .apache
>>>> .felix
>>>> .framework
>>>> .searchpolicy
>>>> .ModuleImpl.findClassOrResourceByDelegation(ModuleImpl.java:618)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> org.apache.felix.framework.searchpolicy.ModuleImpl.access
>>>> $100(ModuleImpl.java:59)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at org.apache.felix.framework.searchpolicy.ModuleImpl
>>>> $ModuleClassLoader.loadClass(ModuleImpl.java:1446)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at java.lang.ClassLoader.loadClass(ClassLoader.java:254)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: at
>>>> java.lang.ClassLoader.loadClassInternal(ClassLoader.java:402)
>>>> Jun 16, 2009 12:38:16 PM
>>>> SEVERE: ... 21 more
>>>> Jun 16, 2009 12:38:16 PM
>>>> org.glassfish.admin.amx.impl.loader.AMXStartupServiceNew
>>>> _loadAMXMBeans
>>>>
>>>
>>> Lloyd Chambers
>>> lloyd.chambers_at_sun.com
>>> GlassFish Team
>>>
>>>
>>>
>
> Lloyd Chambers
> lloyd.chambers_at_sun.com
> GlassFish Team
>
>
>
Lloyd Chambers
lloyd.chambers_at_sun.com
GlassFish Team