Struts2: what is the difference between redirect - redirectionAction - chain

Question

Hi,

I guess they must be somehow base on the good-old "request.sendRedirect" and "RequestDispatcher.forward". They both have pros and cos: - sendRedirect changes the URL but requires 2 request/response, so hard to share data between 2 request - forward is my favorite but it doesn't change the URL, so pressing F5 may cause error.

I don't know much about those 3 from Struts2, I the explanation from apache didn't help much. Could you please explain the diff from them (and if possible, do some references back to "request.sendRedirect" and "RequestDispatcher.forward" that I know quite well)

Thanks in advance!