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By definition, every ActionForm must be a subclass of org.apache.struts.action.ActionForm, which implements java.io.Serializable. In order to implement Serializable, your ActionForm should declare a static final serialVersionUID field of type long. For example:
private static final long serialVersionUID = 7526471155622776147L;
A form's job is data input. It should not be used for data output unless some of that data is used as input too (this does not mean dropdowns, etc). Output data should be stuffed into the request by using request.setAttribute in the Action. You can then access the data in the jsp using the c taglib. Any data that is required for more than one screen, e.g. dropdown data that doesn't change, etc, can be stored in the session (how do you store data in the session?).
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