On Jun 6, 2013, at 2:42 AM, Weijun Wang <weijun.w...@oracle.com> wrote:
> Hi All
>
> I have a method that could throw two kinds of checked exceptions and possibly
> other unchecked ones:
>
> void once() throws One, Two
>
> Now I have a wrapper method that calls once() for multiple times, and want to
> throw the first exception if *all* fails. Now it looks like
>
> void multiple() throws One, Two {
> Exception saved = null;
> for (all chances) {
> try {
> once();
> return;
> } catch (Exception e) {
> if (saved != null) saved = e;
> }
> }
> if (saved instanceof One) {
> throw (One)saved;
> } else if (saved instanceof One) {
> throw (Two)saved;
> } else if (saved instanceof RuntimeException) {
> throw (RuntimeException)saved;
> } else {
> // Not likely, but I've already wrote so many lines.
> throw new RuntimeException(saved);
> }
> }
If you use / are willing to use Guava, you can replace all of the exception if
clauses with:
void multiple() throws One, Two {
for (…) {
…
}
Throwables.propagateIfPossible(saved, One.class, Two.class);
throw Throwables.propagate(saved);
}
http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/base/Throwables.html#propagateIfPossible(java.lang.Throwable,%20java.lang.Class,%20java.lang.Class)
