ALLU

A Controller servlet may perform either a forward or a redirect operation at the end of processing a request.

Forward

• forward is performed internally by the servlet
• the browser is completely unaware that it has taken place, so its original URL remains intact
• any browser reload will simple repeat the original request, with the original URL

Redirect

• redirect is a two step process, where the web application instructs the browser to fetch a second URL, which differs from the original
• a browser reload of the second URL will not repeat the original request, but will rather fetch the second URL
• redirect is always slower than a forward, since it requires a second browser request
• beans placed in the original request scope are not available to the second request

Forward should be used if the operation can be safely repeated upon reload; otherwise, redirect must be used. Typically, if the operation performs an edit on the datastore, then a redirect, not a forward, is required.