review request for 7021209, use try-with-resources in lang, math, util

[Joe Darcy]

David Holmes wrote:
> Hi Stuart,
>
> I'm unclear how try-with-resources applies in different cases. For 
> example, here in Package.java:
>
>       private static Manifest loadManifest(String fn) {
>          try (FileInputStream fis = new FileInputStream(fn);
>               JarInputStream jis = new JarInputStream(fis, false))
>          {
>              return jis.getManifest();
>          } catch (IOException e) {
>              return null;
>          }
>       }
>
> from which code will the the explicit catch block actually catch 
> IOException?

It will catch exceptions from jis.getManifest and from the 
compiler-generated close calls on fis and jis.

> Does this act as-if it were written:
>
>        try {
>           try (FileInputStream fis = new FileInputStream(fn);
>                JarInputStream jis = new JarInputStream(fis, false))
>            {
>              return jis.getManifest();
>            }
>         } catch (IOException e) {
>             return null;
>         }

Yes it does.

-Joe