java.lang.IllegalStateException: Set render parameter has already been call

[Banafshe Bamdad，修改在15 年前。]

Hi,
I set render parameter before sendRedirect in action class like this :

res.setRenderParameter(WebKeys.CHECKED_RESOURCES, listOfUsersIdStr);
sendRedirect(req, res);

but I got the following error :

java.lang.IllegalStateException: Set render parameter has already been called

please help me
Edit/Delete Message

[Heba El Ayoty，修改在13 年前。]

Please read the solution here

http://www.liferay.com/community/forums/-/message_boards/message/7827362

http://forum.springsource.org/showthread.php?t=60113

[delang j，修改在7 年前。]

hi guys,
i came across to this page after i got the same error

java.lang.IllegalStateException: Set render parameter has already been called

if happen after 2nd time form submission after doing some validation.
first i key in duplicate ic
second i key in new ic. then error occur.

if i start again, it happen after 1st submission but wont happen if i press 'ctrl+f5' to refresh the page.
below is my snippet code.

				// Send redirect
				String redirect = PortalUtil.escapeRedirect(ParamUtil.getString(
						req, "redirect"));

				if (Validator.isNotNull(redirect) && SessionErrors.isEmpty(req)) {
					res.sendRedirect(ParamUtil.getString(req, "redirect"));
				}
				
			} catch (Exception e) {
				if (e instanceof DuplicateUserEmailAddressException) {
					SessionErrors.add(req, "duplicate-emel");
				} else if (e instanceof DuplicateUserScreenNameException) {
					SessionErrors.add(req, "duplicate-ic");
				}
				PortalUtil.copyRequestParameters(req, res);
				res.setRenderParameter("mvcPath", "/html/registration/form.jsp");
			}

thanks