How can I get path of resource under WEB-INF/class folder (java ee web dynamic project)

How can I get path of resource under WEB-INF/class folder (java ee web
dynamic project)

I develop web dynamic project in Eclipse. One file, file named 'users.txt'
is located under classes folder (WEB-INF/classes/users.txt).
How I can get relative path of this file in class (base class, not servlet
class)? I will use that path for append several lines of text.