David Winterfeldt wrote:

> Do all version of Tomcat do this?
>

In theory.

Tomcat 3.1 and 3.2 seem to reliably detect cases where the servlet class
you are actually calling has been changed, but they do not always seem
to catch the fact that other classes have been changed.

Tomcat 4.0 uses a different mechanism that reliably catches *all*
changes to classes found in WEB-INF/classes.

In all versions, the application reload only occurs if the changed class
had in fact been used by the application already.  If it hasn't been
loaded yet, there is no reason to restart the app, because no old
version of the class needs to be thrown away.

>
> David
>

Craig


>
> --- "Craig R. McClanahan"
> <[EMAIL PROTECTED]> wrote:
> > Ned Seagoon wrote:
> >
> > > Hi guys,
> > >
> > > Just wondering about the situation that arises
> > when an Action class is
> > > changed in a running struts environment.
> > >
> > > I was under the impression that a single instance
> > of an action class is
> > > created and run inside multiple threads, yet if I
> > recompile the class and
> > > re-run the action then those changes are
> > reflected.
> > >
> > > Is this peculiar to VisualAge for Java (which I am
> > running under) or does
> > > this happen in every environment?
> > >
> > > Actually, this applies to all classes in a project
> > - can I just change them
> > > at will or do I need to do something more?
> > >
> > > Doesn't Tomcat use a special class loader to
> > reload changed servlet classes?
> > >
> > >
> >
> > Tomcat uses a special class loader, but it is global
> > to the entire web
> > app
> > rather than local to a particular class.  When
> > Tomcat recognizes that
> > you have
> > changed a class, it reloads the entire app
> > (destroying the old servlets,
> > initializing the new ones) and even saves your
> > sessions and session
> > attributes
> > if they implement Serializable.
> >
> > This capability is a feature of Tomcat that is
> > commonly implemented, but
> > it's
> > not in the servlet spec.
> >
> > > Regards
> > > Ned
> > >
> >
> > Craig
>
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