Struts 2 does not have "forms" like Struts 1 did. In Struts 2 request parameters are bound directly to fields in the actions class, and this class is placed on top of the stack when the action is executed.
If an action class implements the interface
com.opensymphony.xwork2.ModelDriven then it needs to return an object from the
getModel() method. Struts will then populate the fields of this object with the request parameters, and this object will be placed on top of the stack once the action is executed. Validation will also be performed on this model object, instead of the action. Please read about VisitorFieldValidator Annotation which can help you validate model's fields.
ModelDriven actions, make sure that the Model Driven Interceptor is applied to your action. This interceptor is part of the default interceptor stack
defaultStack so it is applied to all actions by default.
Gangster class (model):
JSP for creating a Gangster: