ActionErrors vs. ActionMessage

ActionMessage

A class that encapsulates messages.

Messages can be either global or they are specific to a particular bean property.

Each individual message is described by an ActionMessage object, which contains a message key (to be looked up in an appropriate messageresources database), and up to 4 placeholder arguments used for parametric substitution in the resulting message.

ActionErrors

A class that encapsulates the error messages being reported by the validate() method of an ActionForm.

Validation errors are either global to the entire ActionForm bean they are associated with, or they are specific to a particular bean property (and, therefore, a particular input field onthe corresponding form)