Command Link : Backing bean setters/getters always invoked

Question

I am trying to understand how to the setters and getters of a request scope managed backing bean are invoked through the navigation flow when using a command link.
It seems that no matter where the navigation rules redirects the page as a result of the action, both the setters and getters of any field bound in the originating page are called.
For example if the originating page has a field name referred by "#{UserBean.name}" to input a username. setName() and getName() are always called as a result of a click on a command link
This behavior is easily seen in a simple JSF example such as http://www.netbeans.org/kb/articles/jAstrologer-intro.html.
If the jsp pointed by "to-view-id" is changed to have no reference to the backing bean or is changed to a jsp with just text, both setters and getters are still invoked.
I could understand why the setters would be invoked (doesn't know ahead of time if the bean will be used?) but at least why the getters?
Last, how to prevent this behavior? The problem is that the backing bean might have complex logic where it will fetch data if a getter is called.
Thanks.

Answer 1

I guess this article might be interesting to get some insights http://balusc.xs4all.nl/srv/dev-jep-djl.html
The setters are invoked to set values and the getters are invoked to get the eventually presetted default values or the previously submitted values.