Session variables in ServletRequest

Question

I need to access session variables through a filter. I don\'t even know if it is possible. In practice, the problem is that the doFilter method type from

Answer 1

Sure you can. ServletRequest allows you access to session that contains attributes. You can review, add, remove and modify attributes whenever you want either in filter, servlet, jsp, session listener. This technique is very useful and especially attended for communication between different components within the same session.

Answer 2

Just cast the obtained ServletRequest to HttpServletRequest.

@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    HttpSession session = request.getSession(false);
    // ...
}

See also:

• Our servlet-filters wiki page