Re: Introspect whether setCharacterEncoding is present..

--- Nic Ferrier <[email protected]> wrote:

<big-snip/>

> 
> What I am asserting is that the statement "Exceptions must not be used
> for control flow" is incorrect. There are situations:
> 
> - where you have to use Exceptions for control flow 
> - where you should use Exceptions for control flow
> 
> These are:
> 
> - multi method FSMs

Maybe you should try Nice (http://nice.sourceforge.net) for these instead. ;-)

--
Martin Cooper


> 
> - predicating behaviour on assertion by Exception
> 
> 
> Clearly if you can't do something any other way it makes the only
> alternative the preferred way. But perhaps you mean it's not
> preferential but we have to do it.
> 
> 
> > Yes, but was the example that triggered this entire debate one of
> > those? Admitted, it's the only obvious way to check if the class
> > exists in the current JVM, but Class.forName() is really intended to
> > get an instance of a class if you expect it to be there, and not as
> > a mechanism to check if the class exists.
> 
> The only obvious way? Or the only way?
> 
> 
> > The fact that the Java standard API doesn't give you a better way to
> > check for the existence of a class without throwing an exception (it
> > doesn't, right? Just checking.) does NOT make the suggested way, The
> > _Right_ Way. It just makes it a convenient hack to get around the
> > limitations of the existing API - also known as, The Only Way.
> 
> What? What planet are you living on? There is no other way. It's not a
> cruddy way to do it: it's THE way to do it. What are we to do when
> writing programs? Not do something because it's inelegant?
> 
> Inelegant and inadvisable are different things.
> 
> 
> > What is a "non-local exit"? What is an "If" check? And what is the
> > requirement here? All we're looking for, is the existence of a
> > class.
> 
> Non-local exits got included in this thread because the suggestion was
> made that Exceptions should not be used for control flow. Non-local
> exits were an obvious and legitimate use for Exceptions that made the
> suggestion a lie.
> 
>  
> 
> > Right. You really _really_ don't like support engineers, do you?
> > (No, I'm not a support engineer either, but I like to think of
> > myself as the sensitive type)
> 
> Actually I do a bit of that from time to time. I'm a hacker. People
> hire me to sort stuff out. I have to read people's code and manage it
> all the time. And I find that reading the code rather than the log
> statements is the most sensible tactic.
> 
> There really is nothing wrong with goto, Sun call it continue or break
> and they use it quite often in JDK code I'm told.
> 
> 
> > And as far as the performance aspect goes, I don't disagree with Nic
> > there. Most times, the effect of throwing Exceptions, on
> > performance, is negligible.
> 
> Good man.
> 
> 
> The only other way I can see of doing Charles' code is this:
> 
>   boolean exists = false;
>   try
>   {
>     Class.forName("com.bull.LoadOf");
>     exists = true;
>   }
>   catch (...Exception e)
>   {}
> 
>   if (exists)
>     ...;
> 
> 
> I prefer Charles' way because there is something in the catch
> handler. Empty catch handler's are bad IMHO (and yes, there are *real*
> reasons why that is so).
> 
> 
> 
> The reason I'm being so pugnacious about this is three fold:
> 
> 1. I believe that it is dishonest to impose stylistic restrictions on
>    use of computer languages 
> 
> 2. I find it patronizing when people suggest that certain things make
>    programs too difficult for support people or newbies or old people
>    or people with glasses or short people or whatever
> 
> 3. I've been implementing Scheme recently in GNU C and continuations
>    are really cool and make you appreciate the whole role of the
>    stack.
> 
> 
> Nic
> 
> 
> 
> Before posting a question, try to find your answer here: 
> <http://www.egroups.com/links/advanced-servlets>
> Announcements should go to: [email protected]
> To Post a message, send it to: [email protected]
> To Unsubscribe, send a blank message to:
> [email protected] 
> Yahoo! Groups Links
> 
> 
=== message truncated ===



		
__________________________________
Do you Yahoo!?
Take Yahoo! Mail with you! Get it on your mobile phone.
http://mobile.yahoo.com/maildemo 


------------------------ Yahoo! Groups Sponsor --------------------~--> 
Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar.
Now with Pop-Up Blocker. Get it for free!
http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/saFolB/TM
--------------------------------------------------------------------~-> 

Before posting a question, try to find your answer here: 
<http://www.egroups.com/links/advanced-servlets>
Announcements should go to: [email protected]
To Post a message, send it to: [email protected]
To Unsubscribe, send a blank message to: [email protected] 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/advanced-servlets/

<*> To unsubscribe from this group, send an email to:
    [email protected]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/