New to Java

Hi I am getting the following error

Exception in thread "main"

java.lang.NoClassDefFoundError:org/apache/log4j/Logger

some possible solution which are not working-
1)put the log jar file in ext library
not working as i have only read access which can not be changed

2)put the absolute class path in manifest file
wont work as abolute path not decided

Now any other idea which should work?