We Keep Coding

Struts 1.x ActionForm Action Class

I've got a simple html page with four buttons. I know how to map the buttons so that the Action Class gets the value of whatever is selected and call a method based on each button in the Action Class. However, what should I do with the Action Form? Can I just leave it blank? It seems that struts requires you to map a bean, yet I'm not really sure what to put in the Action Form, since all that I'm trying to do is call methods in the Action Class.

The struts is what we call nowadays as "action-based" framework. Nowadays most frameworks are what we call "event-based" framework.
It was built to make your life easier when you need to fill huge html forms and then send it to the server.
It was not intended to make your life easier when pressing a button to execute some code on the server and then return with that specific small result.
The main idea of struts was that, big things and change the entire view.
This example (and mabye those ones, takes forever to download) how easier struts made the form-processing easier. see "5. Action (Controller)" of first link.
If not clear, in the time, when there were just servlets, you needed something like this to parse a form.
TL;DR; In the end the ActionForm is there just to help you with your html forms that otherwise you would need to parse by hand instead to receive them as well-formed java beans.

Purpose of ActionForm is to map your fields in your html forms to a corresposnding bean which can be mapped in your strus-config.xml inside the form-bean tag.
Can I just leave it blank? yes the ActionForm is not a required field in <action> tag.

Action Class in Struts 1.x and Struts 2.x

I have a query that in Struts 1.x , in Action class we have Action,Dispatch Action,Lookup Dispatch Action. In the same way in struts 2.x what all action's we have?

In Struts 1 DispatchAction helps us in grouping a set of related functions into a single action. In Struts 2 all the Actions by default provide this functionality. To use this functionality we need to create different methods with the similar signature of the execute() method, only the name of the method changes. It’s a useful mechanism to avoid create separate action classe for each function.
for more info you can visit the following url: url1 and url2 . Hope that helps

Struts and variable post parameters

I'm trying to integrate paypal IPN with my Java Struts web application. According to paypal, there are only 2 variables that are posted with IPN across all transaction types, but there are a bunch of other variables that could possibly be posted.
If a post variable is sent that's not in my action form, then struts returns an error about the form not having the property/setter.
IPN has like 300 variables and I really don't want to have a field for all possible ones. Is it possible in struts to accept post variables that my actionForm may not have accounted for?

If you want to use Post Variables which will not be in Struts Form, you should bypass struts form and use simple html form with struts action classes. Some post variable without getter setter in struts form will throw the exception as you specified. So it is better to use HTML form to gain more flexibility. Off course we should write some functionalities for validation and others again for this type of form.
All we want to say that, you can use simple html forms with struts action classes without any issues. We have already done these type of works in our production applications.
Thanks

In Wicket, what to do write by hand in HTML and what do I generate?

This is my first time with wicket, so please bear with me.
Most examples in wicket show how with a wicket id you can automagically replace the inner HTML with different things. Using this knowledge I've hand written a form in HTML with lots of formatting and JQuery for different things, and only using Wicket to autogenerate the info for 2 select boxes. However when I try to parse the submitted information on the Wicket side, I get confused.
The only way I've figured out that's easy is using RequestCycle.get().getRequest().getRequestParameters(). to get all the passed info. It works, but I don't think that's the ideal way to use Wicket. There also seems to be a way with request handlers but I have no idea where to start, especially since a lot of documentation is out of date with the new 6.0.0 release.
What is the way I'm supposed to use Wicket with forms? Do I hand write most of the form, only let Wicket autogenerate some of the info, and use RequestCycle? Do I write a skeleton form, have Wicket autogenerate the rest, and use lots of submit handlers? Where is this documented in an easy to understand beginner tutorial?
Note: My form has several fields that are created dynamically (think "click here to add more options") and is submitted in the background with AJAX, verified, then cleared. This might complicate the Wicket side of things, but is a functional requirement

With Wicket you can think of HTML markup as if it was a template. Markup is actually almost-standard HTML. You can (and should) define wicket:id attributes for everything that will have certain behavior or logic attached (forms, buttons, links), or require some server-side processing (such as form components or nested custom components or panels). Everything else will be output in the response as it is in the markup.
Wicket will handle form submission and process the request for you. In Wicket, form components are usually defined server-side, and added to a Form component. In the Form component's onSubmit(), Wicket will have already processed the request, and the submitted values will be available in the FormComponent's Models.
So, the ideal way for Wicket to handle form submission would involve the server-side creation of any components in the form.
The following Wicket Examples page shows a basic Form with some FormComponents in it: Wicket Examples - forminput. You can even see its source code.
Also, you might find the following Wicket wiki page useful: How to do things in Wicket - Forms.
Regarding dynamic component creation, whenever a new dynamic component has to be created, you could for instance make an Ajax request that creates the component server side (wrapped in a ListView, for example), and get markup refreshed in the ajax callback.
There's an example of such a list here: Wicket in action - Building a ListEditor form component
Just to add, I found the Wicket in Action book to be an excellent resource for learning Wicket. Chapter 6 - Processing user input using forms elaborates on the subject.

Confused: Role of Beans in JSF2 in comparison to classical MVC Controllers

i have a question that is more design and architecture related. I am coming from a classical MVC based background and have to get my hands dirty on JSF2. I read the IBM articles on JSF2 (http://www.ibm.com/developerworks/library/j-jsf1/) and think i understand the overall concept.
I started to get in touch with JSF2 trough ROO. I have the feeling that ROO (maybe this is true for any JSF2-Type App, or maybe not) is making very strange/unclear use of beans. It is in general really not clear to me what the actual role of a Bean is! For example, if i have a view with a form that is for editing a single user-entry, i would initialize the user in a, lets call it UserBean (maybe store in in a member variable) and access this variable trough getters. If i now want to overview all users, i would again render the view in in the UserBean hold a collection of users and again access this collection trough getters. The previous description is actually the way i would do things with jsf. This means i would user the UserBean more as a statefull-service as a controller.
In a typical controller situation i would create for every type of action (list user, edit user, view user, etc) a separate controller, with specific initialized data and this way i would separated the context of the logic by controllers.
I often make use of context specific services, e.g. if i handle user's often an spread over the application, i create a user-service that handles user specific logic that is maybe to complex to be put into the itself. If i now for example look into roo generated Beans, i would find methods that programatically render forms, input fields, labels, that again store list's of users, boolean fields that indicate if data had already been loaded, single user members and a lot of methods that more look like to be put into a UserService (or whatever). I am wondering if this is the way JSF2 is intended to be used, in words: pushing everything that is related to one context into on bean, not making use of service and writing "super-controller-beans" that handle everything.
I don't really know if you get the question right, but what would maybe help me is, a hint to
a very exemplary and commendable example application that makes use of beans the way they where intended to be used in combination with jsf2 features and usecases that for example implement basic CRUD usecases around a given type of entity. (One big confusing point is, that in my case ROO always makes use of AJAX and javascript stuff like Modal-Dialogs to implement CRUD logic. I wonder if with JSF there is a more classical way to to this?[With 'classical' i mean for example URL-Based views and separated views for listing, editing and viewing entities])
a resource that enlightens typical "thats-the-way-the-good-guys-do-it" JSF-Patterns (maybe this is J2EE Patterns?).
Thanks you so much!
Please feel free the push me to concretize specific points if i am not clear!

The link for JSF2 you have posted points to JSF1.2 article. In case you want to start of with JSF2 or JSF I suggest following links.
JSF 2.0 Tutorial # mkYong.com
BalusC JSF blog
Stackoverflow wiki for jsf
I'll suggest start with plain vanilla JSF rather than ROO with JSF to get a hang of JSF.
To answer your question
First link provides you with simple jsf examples, in JSF you can have both ajax based and classical way of submitting form. In JSF 1.x versions ajax was not part and parcel of JSF it was implemented by third party component library mainly RichFaces and PrimeFaces to name few. In JSF2 there is inbuilt support for ajax, this does not apply third party components are no longer required, they still provide some extended features. I'll suggest go through this link to find differences between JSF 1.x and JSF 2.
Patterns I am not aware of as such as specific to JSF apart code can be categorized in model - view - controller. Typical case Person represents model, PersonMangedBean plays role of controller which plays central role of getting data from view(jsp/facelets) and after processing data in bean itself or service beans handles navigation to classic views may be listPersons.xhtml.
JSF managed beans are not "super-controller-beans" handling every thing in that bean. I try to categorize things the way you mentioned i.e. have a service layer where we have all business logic may be EJB or Spring managed bean and it decouples at-least business logic away from view technology JSF whereby it(service) can be reused somewhere else as a library if designed properly.
Tip: JSF is component based framework not an action based and it has lifecycle of its own, do get a grip of that life-cycle will save lots of time and proper understanding of the framework. This link though for JSF 1.x holds good for JSF2 too, for basic understanding of life-cycle.
Hope this helps.