Can be used to validate the properties that have been set for this non-HTTP request, and return an ActionErrors
object that encapsulates any validation errors that have been found. If no errors are found, return null
or an ActionErrors
object with no recorded error messages.
The default implementation attempts to forward to the HTTP version of this method.
@param mapping The mapping used to select this instance
@param request The servlet request we are processing
@return The set of validation errors, if validation failed; an emptyset or
null
if validation succeeded.