In fact, in the catch(Exception ex) branch there should be a return
mapping.findForward("generalError"); which I didn't include in the example .
But generally you're approach is better, and more appropriate.
Do yoy have any real examples on Exception handlers, or any links to which you
may point me ?
Thanks,
Ovidiu
----- Original Message -----
From: "Kris Schneider" <[EMAIL PROTECTED]>
To: "Struts Users Mailing List" <[EMAIL PROTECTED]>
Sent: Thursday, November 20, 2003 4:36 PM
Subject: Re: Simulating multiple inheritance for Action and DispatchAction
Well, what if you don't provide a handler (or a standard servlet error page)? An
unhandled exception will be propogated to the container which will return a
status code 500 to your users. I wouldn't really call the resulting generic
"internal server error" user friendly.
BTW, your code for catching Exception just prints a stacktrace, logs a message,
and then falls through to return whatever "forward" has been set to (null?).
Quoting Ovidiu EFTIMIE <[EMAIL PROTECTED]>:
> For BaseException there is not really a need to catch it in BaseAction,
> because
> I'll have a handler, but for Exception I don't know. Is it a good practice
> to
> declare may own handler?
>
> Ovidiu
>
> ----- Original Message -----
> From: "Kris Schneider" <[EMAIL PROTECTED]>
> To: "Struts Users Mailing List" <[EMAIL PROTECTED]>
> Sent: Thursday, November 20, 2003 4:02 PM
> Subject: Re: Simulating multiple inheritance for Action and DispatchAction
>
>
> Why not just declare handlers for *both* BaseException and Exception in
> struts-config?
>
> Quoting Ovidiu EFTIMIE <[EMAIL PROTECTED]>:
>
> > I agree with you regarding the leading I ;
> > I've implemented the setServlet method after sending the mail :)
> > Yes you're right about GeneralImpl it must be final .
> > I'm overiding execute just for BaseAction of course :), and I do it to
> > catch
> > exception that are not applicational
> > Something like this
> > try{
> >
> > forward = executeAction(....);
> > }catch(BaseException bex){
> > log.error(bex);
> > //to be catched by the handlers declared in struts-config.xml
> > throw bex
> > }catch(Exception ex){
> > ex.printStackTrace();
> > log.fatal(e);
> > }
> > return forward;
> >
> > Ovidiu
> >
> >
> > ----- Original Message -----
> > From: "Kris Schneider" <[EMAIL PROTECTED]>
> > To: "Struts Users Mailing List" <[EMAIL PROTECTED]>
> > Sent: Thursday, November 20, 2003 2:13 PM
> > Subject: Re: Simulating multiple inheritance for Action and
> DispatchAction
> >
> >
> > The general approach is probably fine, although naming interfaces with a
> > leading
> > "I" makes me gag ;-). However, this seems like a bad idea:
> >
> > public abstract class BaseAction extends Action implements IGeneral {
> > private static GeneralImpl general;
> > public BaseAction() {
> > general = new GeneralImpl(servlet);
> > }
> > ...
> > }
> >
> > Every time an instance of BaseAction is created, the *static* field
> > "general"
> > gets reset. Also, where is BaseAction getting the "servlet" arg to pass
> to
> > the
> > GeneralImpl constructor? Instead, perhaps:
> >
> > public abstract class BaseAction extends Action implements IGeneral {
> > private final IGeneral general;
> > public BaseAction() {
> > this.general = new GeneralImpl();
> > }
> > public void setServlet(ActionServlet servlet) {
> > super.setServlet(servlet);
> > this.general.setServlet(sevlet);
> > }
> > ...
> > }
> >
> > Of course, that means adding a setServlet method to IGeneral and
> > GeneralImpl.
> > I'm also not sure why you'd override execute just to call executeAction.
> > You
> > certainly wouldn't want to override DispatchAction's execute method,
> right?
> >
> > Quoting Ovidiu EFTIMIE <[EMAIL PROTECTED]>:
> >
> > > Hi,
> > > In my application I need to have my Actions and my DispatchActions.
> > > Each one of this actions must have the same base class in which I have
> > > common
> > > methods to both of them.
> > > My solution is to first declare an interface IGeneral in which I'm
> > declaring
> > > the
> > > common methods, then create an implementation class,GeneralImpl.Next
> thind
> > to
> > > do
> > > would be to create my base classes BaseAction and BaseDispatchAction
> and
> > > this
> > > two must implement IGeneral, and in their implementation they should
> > delegate
> > > to
> > > a private static member of type GeneralImpl, which will handle this
> > > methods.
> > > Example:
> > > <code>
> > > public interface IGeneral{
> > > public Connection getConnection() throws SQLException;
> > > ...........
> > > public User getUser(HttpServletRequest req);
> > > }
> > > </code>
> > >
> > >
> > > Then I'm creating the implementation for this methods:
> > >
> > >
> > > <code>
> > > public class GeneralImpl implements IGeneral{
> > > private ActionServlet servlet;
> > > public GeneralImpl(ActionServlet srv){
> > > servlet = srv;
> > > }
> > > public Connection getConnection() throws SQLException{
> > > //code here
> > > }
> > > ...........
> > > public User getUser(HttpServletRequest req){
> > > //code here
> > > }
> > > }
> > > </code>
> > >
> > > Now I create the base Actions
> > >
> > > <code>
> > > public abstract class BaseAction extends Action implements IGeneral
> {
> > > private static GeneralImpl general;
> > > public BaseAction (){
> > > general = new GeneralImpl(servlet);
> > > }
> > > public ActionForward execute(ActionMapping
> mapping,ActionForm
> > > form,HttpServletRequest request,HttpServletResponse response){
> > > return executeAction(ActionMapping mapping,ActionForm
> > > form,HttpServletRequest request,HttpServletResponse response)
> > > }
> > > public abstract executeAction(ActionMapping
> > mapping,ActionForm
> > > form,HttpServletRequest request,HttpServletResponse response);
> > > public Connection getConnection() throws SQLException{
> > > return general.getConnection();
> > > }
> > > public User getUser(HttpServletRequest req){
> > > return general.getUser(req);
> > > }
> > > }
> > > </code>
> > > The same for the DipatchAction.
> > >
> > > The question is anoybody has used something like this ? It this a good
> > thing
> > > to
> > > do it ?
> > >
> > > Tanks in advance and sorry if the text it's too long
> > > Ovidiu
> >
> > --
> > Kris Schneider <mailto:[EMAIL PROTECTED]>
> > D.O.Tech <http://www.dotech.com/>
>
> --
> Kris Schneider <mailto:[EMAIL PROTECTED]>
> D.O.Tech <http://www.dotech.com/>
--
Kris Schneider <mailto:[EMAIL PROTECTED]>
D.O.Tech <http://www.dotech.com/>
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