Mr. Xiaodongx asked me this question, did not do experiments, did not dare to conclusion, and now we wrote the following code TEST.
Code Block 1
Public Class TestAction Extends Action {Public ActionForward Extende (ActionMapping Mapping, Actionform Form, HttpservletRequest Request, httpservletResponse response) throws exception {
Testform actionform = (testform) form; actionform.setp ("p1"); testform actionform2 = new testform (); actionform2.setp ("p2"); request.getSession (). Setttribute ("vo", actionform2); request .SetaTRibute ("Vo", ActionForm);
Return mapping.findforward ("input");
}
Code blcok2
At this point, P1 is displayed.
If you blocked the green code, the page displays P2
So draw conclusions
Tag first reads data from the request, not read from the session, no error
