Re: Catching Thrown Exceptions

From:
Daniel Pitts <newsgroup.nospam@virtualinfinity.net>
Newsgroups:
comp.lang.java.help
Date:
Thu, 23 Feb 2012 14:47:13 -0800
Message-ID:
<Slz1r.6732$VR6.2044@newsfe14.iad>
On 2/23/12 9:20 AM, Davej wrote:

On Feb 21, 6:14 pm, Lew<no...@lewscanon.com> wrote:

"Davej" wrote:

Ok, I apologize for not including specific details.
This is a jsp file and I had the following inside
a try block...

if ( condition )
{
    throw exception;
}


You shouldn't have Java source in a JSP page.

Perhaps you are aware that 'exception' is a predefined
variable in an error JSP that has value only when there
actually is an exception? Or perhaps you mean something
different by "compiled" than I do? You send us these
code fragments that yield no context. On the face of it
I don't know how your code fragment was able to compile
successfully.


 From what I have read it is perfectly acceptable to have code in a JSP
page. It has been said that if there is more HTML than code a JSP is
the proper thing to use. If there is more code than HTML then a
servlet is the proper thing to use. Do you disagree with this?

I do disagree. If you have business logic, it should be in Java, if you
have (HTML or XML) View logic it makes sense to be in JSP (or some other
templating language). The only "code" that should be in JSPs is
rendering code. A well defined model (which handles exceptions
appropriately), and a controller (which probably does preprocessing to
avoid those exceptions) are important parts of any webapp.

Yes, I had a syntax error. No I did not know that exception was a
system variable. No I don't care about documenting the error in this
tiny example program. And no I am not yet comfortable with JIT
compiles. I don't know how to force Netbeans to do a complete
compile.


JSPs are typically compiled by the application container, so not
necessarily by your "build" system. It is a compile error that doesn't
show up until your system attempts to compile that JSP. Yet another
reason to have Java code separate from JSP code.

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