[EMAIL PROTECTED] wrote:
> Daniel John Debrunner wrote:
>
>> [EMAIL PROTECTED] wrote:
>>> You would at least need to have one per thread.
>> Why? If I have a singleton as a static and never modify it, I can safely
>> throw it in multiple threads. It will have the fixed meangingless stack
>> trace, but this to handle a special case.
>
>
> The stack trace isn't created when the Exception object is constructed,
> it's created when it's thrown. If you throw the same exception object
> from multiple threads, they will interfer with each other in
> unpredictable ways.
That's not what I see in jdk 1.4.2, from IBM & Sun and jdk 1.5. Here's a
simple program that creates an exception in the method b() but throws it
in a(). I always see b() in the stack trace.
java.lang.Exception: from b
at te.b(te.java:20)
at te.a(te.java:15)
at te.main(te.java:6)
I've always seen exceptions have the stack trace of where they were
created. That's also what the jdk 142 javadocs say for Throwable:
'A throwable contains a snapshot of the execution stack of its thread at
the time it was created'
public class te
{
public static void main(String[] args)
{
try {
a();
} catch (Exception e)
{
e.printStackTrace(System.out);
}
}
public static void a() throws Exception
{
throw b();
}
public static Exception b()
{
return new Exception("from b");
}
}
Dan.
