title: How Spring MVC Form handling works?
body: <p>I have learned how to use Spring MVC 3, but I am very interested in background of it. One of the most interesting things to me is forms handling.</p>
  
  <p>So far, I know that every http request in handled by dispatcher, mapped to proper controller. Controlles make some behind work, and than selects JSPX page to be loaded, and sends attributes to it. JSPX in compiled by container (Tomcat, etc...) to another servlet. Than web page is send back in http response.</p>
  
  <p>This seems all right for me, in most case scenarios. But, form handling is different. In <code>&lt;form:form&gt;</code>  tag, you defined object and attributes mapping to it. But in logic mentioned above, it actually never gets invoked. I mean, user requests page with form. So controller renders it. Than user send form, and some save method is invoked by dispatcher. But how does Spring know how to map incomming attributes, if they are described in JSPX that is not invoked?</p>
  
  <p>Also, if you know any good, preferably web, resource on Spring MVC background, post a link. Thank you.</p>