Re: Finding Error in Applet.
Sanny wrote:
You are talking on other matters instead of the problem
1. Why I do not put "?" Mark. That has nothing to do with what I
asked.
Why are you unwilling to use question marks to mark your questions?
2. How to Trim Again nothing to do with my problem
But everything to do with people's willingness and ability to volunteer their
precious time to help you with it.
3. Write nullException as NoClassDefFoundError
If you report the situation inaccurately, advice given will be inaccurate and
likely useless.
Accurate and rigorous information is needed to be of any assistance. Are you
sure you don't want to provide that?
My Question is Simple and I restate again
I use double buffering in my applet. I hope you understand what is
double buffering. So my applet cannot be launch by Java Viewer as it
gives nullException.
There is no such exception in the standard Java API. Did you mean
NullPointerException?
If so, you should say so. Inaccurate information leads to inaccurate and
useless diagnoses.
But my Applet runs without any problem on Web Browsers like Explorer/
Netscape etc.
Sometimes 1 in 10 times it hangs. I just want to get details of
function/ Variable which hang the Program. And also what type of error
is called.
There may not be an error. If an Exception or Error or any other Throwable
were thrown, you'd have gotten a message to that effect already.
Did you?
1. Arrayoutof Bounds
2. Division by Zero
3. Memore Full
These are very different categories of problems, reported by different types
of Throwable in Java.
Division by zero doesn't even necessarily throw an exception. It could just
yield a valid value.
And also I would like to get the Variables [sic] values when it hangs.
You need a reliable way to detect a hang and break out of it for that to
happen. Infinite loops and thread deadlock are examples of situations that
will not spin out any throwables.
A good logging package, like the inbuilt java.util.logging package or the
open-source log4j library, can report the type of information you seek.
If you log at FINE (java.util.logging) or DEBUG (log4j) level, or more
detailed, you can spin off log information at various points in your algorithm
that can help diagnose even such problems as infinite loops and thread deadlock.
For that I want to use try{ } Catch Statement. But I am not aware how
to do it on all functions?
Do I need to put try{}catch seperately on each function or I can put a
try{ } catch to all function by some way. I just want to know why the
Program hangs 1 in 10 times.
try-catch probably will not reveal the source of your problem.
Use try-catch whenever the code explicitly has a path that might throw an
exception. In the catch block be sure to use your logging library to report
the exception.
In other situations where try-catch will not help, logging still will.
<http://java.sun.com/javase/6/docs/api/java/util/logging/package-summary.html>
<http://logging.apache.org/log4j/1.2/index.html>
--
Lew