class retunring nullPointerException??

Thread view:

elh.maayan@gmail.com - 20 Apr 2007 09:55 GMT

hi..
we have a homegrown Web Framework, which lives in jboss, each time we
update our code application coe via ant script ,the framework stops
and starts jboss, anong the procedures to start jboss is a loading up
hbm files with hibernate spring orm, problem is, when start the server
the second time, we get a nullPointerException when attempting to map
one of the classes. we traced it down to hibernate mapping a class
which was meant to store OracleBlob, in one of it's code hibernate
uses:

EnumeratedType.class.isAssignbleFrom(..)

however the class property returns nullPointerException!!, hos is that
possible ? (EnumeratedType is an interface).

Reply to this Message

Thomas Fritsch - 20 Apr 2007 12:08 GMT

[...]

> EnumeratedType.class.isAssignbleFrom(..)
>
> however the class property returns nullPointerException!!,

You mean "*throws* NullPointerException", don't you?

> hos is that possible ? (EnumeratedType is an interface).

Carefully read the API doc of Class#isAssignableFrom
<http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Class.html#isAssignableFrom(ja
va.lang.Class)>

There you'll find, that the method-call isAssignableFrom(cls) throws a
NullPointerException, if cls is null.

Signature

Thomas

Reply to this Message

elh.maayan@gmail.com - 20 Apr 2007 16:40 GMT

i'm sorry i meant throws null..

what you said makes sense, BUT i didn't say isAssignableFrom throws
it, i said that doing in eclipse a watch expression
'PersistentEnum.class',
THAT throws an exception.

look at the stack trace, the isAssignableFrom is in line 168, i had
brake point there, and tried the watch expression.

java.lang.NullPointerException
at org.jboss.mx.loading.LoadMgr3.beginLoadTask(LoadMgr3.java:
143)
at
org.jboss.mx.loading.UnifiedClassLoader3.loadClassImpl(UnifiedClassLoade
at
org.jboss.mx.loading.UnifiedClassLoader3.loadClass(UnifiedClassLoader3.j
at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:
302)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at net.sf.hibernate.type.TypeFactory.class$(TypeFactory.java:
71)
at
net.sf.hibernate.type.TypeFactory.heuristicType(TypeFactory.java:168)

Reply to this Message

Thomas Fritsch - 20 Apr 2007 18:14 GMT

> i'm sorry i meant throws null..
>
[quoted text clipped - 16 lines]
> at net.sf.hibernate.type.TypeFactory.class$(TypeFactory.java:71)
> at net.sf.hibernate.type.TypeFactory.heuristicType(TypeFactory.java:168)

Looking at your stack trace (especially its top lines) it seems the
NullPointerException is caused by a bug in JBoss's classloader.

Signature

Thomas

Reply to this Message

elh.maayan@gmail.com - 21 Apr 2007 22:41 GMT

anyway to fix this?

Reply to this Message

class retunring nullPointerException??

Free Magazines