If in a JSP page I create a new file only giving it's name, it's created in the /bin directory of TOMCAT folder, rather in the same folder of the .jsp.
I'm not sure why this happens, seems to be not intuitive.
It's definitely intuitive, as the current directory of the running process is the bin folder.
You can try something like:
ServletContext context = session.getServletContext();
String realContextPath = context.getRealPath(request.getContextPath());