code: private boolean isRequestURLEqualsExitPageHost(HttpServletRequest req, String logoutURLhost) {
          boolean acceptURL = false;
          try {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
                  Tr.debug(tc, "about to attempt matching the logout exit url with the domain of the request.");
              StringBuffer requestURLString = req.getRequestURL();
              URL requestURL = new URL(new String(requestURLString));
              String requestURLhost = requestURL.getHost();
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
                  Tr.debug(tc, " host of the request url is: " + requestURLhost + " and the host of the logout URL is: " + logoutURLhost);
              if (logoutURLhost != null && requestURLhost != null && logoutURLhost.equalsIgnoreCase(requestURLhost)) {
                  acceptURL = true;
              }
          } catch (MalformedURLException e) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "caught Exception trying to form request URL object: " + e.getMessage());
              }
          }
          return acceptURL;
      }
docs: Attempt to match the request URL's host with the URL for the exitPage this might be
  the case of a proxy URL that is used in the request.
  
  @param req
  @param acceptURL
  @return