I need to add a filter on some page's that checks if some Session-attributes are set.
What I want to achieve is: User tries to directly navigate to a page. On that page, there are 3 Portlets that need SessionVariables. Those are set by the previous page. So, if those variables are not available, there has to happen a redirect to the previous page.
So I was looking to add a filter hook, so the class implements Filter
public class SampleFilter implements Filter {
    @Override
    public void destroy() {
        /* Destroy method*/
    }
    @Override
    public void doFilter(
            ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) {
        /* I need to access the PortletSession here! */
        filterChain.doFilter(servletRequest, servletResponse);
    }
    @Override
    public void init(FilterConfig filterConfig) {
        /*Method to init filter..*/
    }
}
Is it possible to check a variable in the doFilter() Method, that I've set with the session.setAttribute("name", value, PortletSession.APPLICATION_SCOPE);?
                        
Ok, I found this:
Because the Session Attributes where scoped "APPLICATION_SCOPE", It is possible to access them through the HttpSession: Example
That's all!