> I still find the use of addSuppressed in initCause to be questionable.
> Given:
>
> catch(SomeException s) {
> sharedException.initCause(s); // oops already has a cause
> throw sharedException;
> }
>
> then the ISE isn't suppressing 's', but replacing/suppressing
> sharedException in my view, as it is what would have been thrown had the
> ISE not occurred.
I agree. I think makes sense to swap the ISE cause and suppressed arguments
because the root cause should be the most important throwable to see in a log
file.
In David's example, that would be 's' or the root cause of 's'. Also when the
two arguments are swapped the line numbers are in descending order.
===========JDK 7 testcase===========================
public static void main(String[] args) throws Exception {
final Throwable cause = new NoClassDefFoundError();
final Throwable THIS = new ClassNotFoundException();
try {
THIS.initCause(cause); //It's a trap!!
} catch (IllegalStateException ISE) {
ISE.initCause(cause); //swapped
ISE.addSuppressed(THIS); //swapped
ISE.printStackTrace();
}
}
java.lang.IllegalStateException: Can't overwrite cause
at java.lang.Throwable.initCause(Throwable.java:456)
at Main.main(Main.java:33)
Suppressed: java.lang.ClassNotFoundException
at Main.main(Main.java:31)
Caused by: java.lang.NoClassDefFoundError
at Main.main(Main.java:30)
===============================================
Jason
