Howdy all!
I was considering employing a "Master Action Class" from which I could inherit smaller
action classes in order to make effective use of shared code. However, I want to
ensure that the code remains thread-safe. Here's an example of what I was considering:
public abstract class MainAction extends TilesAction {
protected DynaValidatorForm form = null;
protected ActionErrors errors = null;
protected ActionMessages messages = null;
protected SimpleDateFormat df=new SimpleDateFormat("MM/dd/yyyy",Locale.US);
public abstract ActionForward execute(ActionMapping mapping, ActionForm
baseForm, HttpServletRequest request, HttpServletResponse response);
protected boolean validLogon(HttpSession session) {
//check session to ensure that it's not invalidated
}
protected void startSubTransaction(HttpSession session) {
session.setAttribute(Constants.SUB_TRANSACTION_IN_PROGRESS,
Constants.TRUE);
}
protected void endSubTransaction(HttpSession session) {
session.setAttribute(Constants.SUB_TRANSACTION_IN_PROGRESS,
Constants.FALSE);
}
}
public class SubAction extends MainAction {
private static Logger logger = Logger.getLogger(SubAction.class);
public ActionForward execute(
ActionMapping mapping,
ActionForm baseForm,
HttpServletRequest request,
HttpServletResponse response) {
form = (DynaValidatorForm) baseForm;
errors = new ActionErrors();
if (!validLogon(request.getSession())) {
return (mapping.findForward("logon"));
}
//Check for errors
if (!errors.isEmpty()) {
saveErrors(request, errors);
return (mapping.findForward("error"));
}
saveToken(request);
startSubTransaction(request.getSession());
return (mapping.findForward("success"));
}
}
What with the form, errors & messages variables being defined at class level in the
parent class, could I run into some issues with instance variables being overwritten
with different requests? Should I move them into the individual execute() methods of
the subclasses of MainAction?
Thanks,
Brent
-----Original Message-----
From: e-denton Java Programmer [mailto:[EMAIL PROTECTED]
Sent: Monday, December 22, 2003 1:39 PM
To: Struts Users Mailing List
Subject: Re: Example of a non-threadsafe Action?
Hi! Don't store any request related items in static or instance variables.
----- Original Message -----
From: "David Erickson" <[EMAIL PROTECTED]>
To: "Struts Mailing List" <[EMAIL PROTECTED]>
Sent: Monday, December 22, 2003 1:02 PM
Subject: Example of a non-threadsafe Action?
> Hey I have been reading a lot about threading lately from the JLS and
> otherwise.. but my question is what would be an example of a
non-threadsafe
> action? Struts manual said that only one instance of an action exists in
> the JVM.. and when I run an action each thread creates its own versions of
> all the variables within the action correct? So assuming I'm not
accessing
> some outside 'global' variable, everything is inherintly threadsafe right?
>
> If anyone can give me an example of what 'not' to do that would help
> tremendously.
> thanks,
> David
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
>
>
____________________________________________________________
This message sent using iMail from I-Land Internet Services.
http://www.iland.net
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
