I hope this is the right section. I have been trying to fix this problem for the past few days with no success and hope someone here can help me out.

When I run tomcat7, I get the following error
log4j:ERROR Could not parse file [null/WEB-INF/classes/log4jdev.xml].
java.io.FileNotFoundException: C:\eclipse-jee-juno-SR1-win32\eclipse\null\WEB-INF\classes\log4jdev.xml (The system cannot find the path specified)
It doesn't find the log4jdev.xml file(which is present) because half of the path is missing (null) and I don't know why this is happening.
The class where it gets that path is Log4JInit.java - the following code when executed returns null

String prefix =  getServletContext().getRealPath("/");
and then when at the end this line sets the path
because the prefix is null, the full path becomes invalid.

I don't know why this is happening and how I should fix it in order to get the right path.