CloneNotSupportedException should extends RuntimeException not Exception

[Mike Duigou]

Seems reasonable to me at first glance. I am still reviewing this but wanted to add two clarify notes:

- This change means that CloneNotSupportedException is no longer a checked exception. This change is generally harmless.

- Cases where CloneNotSupportedException is being caught were probably added because it was a checked exception. They can be safely left in.

Mike


On Oct 14 2012, at 09:19 , Remi Forax wrote:

> Hi everybody,
> CloneNotSupportedException is thrown when a developer calls Object.clone() and forget to mark the current object as Cloneable. Because it's clearly a developer error, CloneNotSupportedException should be a subtype of RuntimeException and not of Exception.
> 
> I believe this change is backward compatible because RuntimeException is a subclass of Exception,
> so I propose to first change CloneNotSupportedException to extends RuntimeException.
> 
> diff -r ff641c5b329b src/share/classes/java/lang/CloneNotSupportedException.java
> --- a/src/share/classes/java/lang/CloneNotSupportedException.java Sat Oct 13 10:15:57 2012 +0100
> +++ b/src/share/classes/java/lang/CloneNotSupportedException.java Sun Oct 14 18:16:35 2012 +0200
> @@ -42,7 +42,7 @@
>  */
> 
> public
> -class CloneNotSupportedException extends Exception {
> +class CloneNotSupportedException extends RuntimeException {
>     private static final long serialVersionUID = 5195511250079656443L;
> 
>     /**
> 
> 
> And then to clean up the whole JDK (in several patches) to remove all the unnecessary
> try/catch like the one in by example ArrayList.clone()
> 
>    public Object clone() {
>        try {
>            ArrayList<?> v = (ArrayList<?>) super.clone();
>            v.elementData = Arrays.copyOf(elementData, size);
>            v.modCount = 0;
>            return v;
>        } catch (CloneNotSupportedException e) {
>            // this shouldn't happen, since we are Cloneable
>            throw new InternalError(e);
>        }
>    }
> 
> will become
> 
>    public Object clone() {
>        ArrayList<?> v = (ArrayList<?>) super.clone();
>        v.elementData = Arrays.copyOf(elementData, size);
>        v.modCount = 0;
>        return v;
>    }
> 
> 
> cheers,
> Rémi
>