This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
There is no such equivalent. A Struts <html:radio> tag is tied to the ActionForm bean property specified in the tag. If the ActionForm property is set to the value specified in the tag, the button will show as checked. Otherwise, it will show as unchecked. Example:
In the above example, if the form bean property "color" contains "blue, the second button will be checked.