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From Andrej Rosenheinrich <>
Subject NullPointerException in AdaptiveClassLoader
Date Fri, 31 Aug 2001 15:37:22 GMT

I posted this question once in the user-list, but got no reply. After 
getting no help and starting to look at the sourcecode this thing gets 
even more weird to me, so I hope you excuse that I now post it to the 

I broke down my question to a simple example. I have a html-page, 
calling a servlet and submitting one parameter. Calling this servlet I 
am getting:

Error: 500
Location: /aba2/test
Internal Servlet Error:
java.lang.NullPointerException at 
( (pc 145) at 
( (pc 18) at 
( (pc 38) at 
org.apache.tomcat.core.ServletWrapper.init ( (pc 
33) at org.apache.tomcat.core.Handler.service ( (pc 19) 
at org.apache.tomcat.core.ServletWrapper.service 
( (pc 140) at 
( (pc 250) at 
org.apache.tomcat.core.ContextManager.service ( 
(pc 3) at 
( (pc 388) at 
( (pc 73) at 
( (pc 132) at ( 
(pc 11)

My servlet, the html-file, the web.xml file and server.xml-file are 

After having no idea at all what's going on I took a look at the 
sourcecode. First, I am using tomcat 3.2.1 under OpenVMS. Unfortunatly I 
couldnt get the code for version 3.2.1, only for 3.2.3. So I have to 
assume that the code for this class didnt change (did it?). Looking at 
the method loadClass in AdaptiveClassLoader I actually dont see a 
possible source for a NullPointerException. There can be a result value 
null, but nowhere a NullPointerException is thrown, as far as I looked 
at the statements in this method.

My questions: what can cause such an exception? did the class 
AdaptiveClassLoader change from 3.2.1 to 3.2.3? where is the point this 
exception is thrown?
Another question, under OpenVMS I have my doubts that an errormessage 
OutOfError is necessarily related to memory. What else can cause such an 
error? Bufferlimits? Processlimits? Is it possible/planned to give more 
specific errormessages? Is it possible to get involved in this project 

Hope to not disturb anyone

Greetings, TIA
Andrej Rosenheinrich

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