Say you have 3 buttons on your form: add, delete, and update. If your website is in English and you're not planning to use internatoinalization, you would code the three buttons:
<html:submit property="action">add</html:submit>
<html:submit property="action">update</html:submit>
<html:submit property="action">delete</html:submit>
You could then use DispatchAction and code the methods add(), update(), and delete(), and
Struts would forward to the appropriate method based on the button pressed.
However, if you use internationalization, this won't work because the label of the button could be in any number of languages. In this case, you need to use LookupDispatch action and code your
JSP like this:
<html:submit property="action"><bean:message key="label.add" /></html:submit>
<html:submit property="action"><bean:message key="label.update /></html:submit>
<html:submit property="action"><bean:message key="label.delete" /></html:submit>
You'll then code the getMethodKey() to find the appropriate method based on the message key. That way, regardless of what language is actually used at runtime, Struts will still dispatch to the correct method.