Re: tomcat error..

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.help
Date:
Fri, 18 Jan 2008 20:43:04 -0500
Message-ID:
<t9udnSqbmbo1yAzanZ2dnUVZ_u2mnZ2d@comcast.com>
maya wrote:

well, the weird thing is, sometimes it shows in what line in JSP servlet
the error is, I find my way to the servlet and find line causing error,
which is quite useful, but sometimes it doesn't tell you anything, like
example I posted above.. (tomcat [sic] "doesn't execute JSP's" what....????
 tomcat [sic] is not the servlet engine???)


Tomcat is the servlet engine, but it doesn't execute JSPs, it compiles them
into Java source, then compiles the Java source into bytecode, then it
executes the bytecode.

one of the main problems I have in general with JSP's is that sometimes
they stop generating interface code "in midstream" and I have no idea


Because an exception occurred during execution of the servlet, usually NPE as
Wojtek points out.

why.. someone here suggested defining an error pg and stuff, which I
did, but it's also not too useful, as sometimes it doesn't show error at
all, it just says "Exception: " then nothing...


NullPointerException, possibly.

I don't use any IDE at all, develop in HomeSite (HTML editor) and that's


That is going to be next to useless in debugging JSPs.

it.. (if doing servlets or stand-alone classes I compile "manually" in
DOS shell.. I guess it might be a good idea for me to start using
Eclipse or something...;)


IDEs are best for things like debugging; command-line tools are best for
building the final deployment artifacts.

what IS log4j... at work we use weblogic [sic], not tomcat [sic].. [sic] I always see
"log4j" (or something like that) in weblogic console when booting up
weblogic..


GIYF.

log4j is Apache's logging library. Java also has the java.util.logging
package; both provide logging at dynamic levels of detail which can aid
tremendously in the maintenance of deployed software.

--
Lew

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