RFR: 8303832: Use enhanced-for cycle instead of Enumeration in JceKeyStore

[Michael StJohns]

On 3/8/2023 2:19 PM, Andrey Turbanov wrote:
> java.util.Enumeration is a legacy interface from java 1.0.
> There is couple of places with cycles which use it to iterate over collections. We can replace this manual cycle with enchanced-for, which is shorter and easier to read.
>
> -------------
>
> Commit messages:
>   - [PATCH] Use enhanced-for cycle instead of Enumeration in JceKeyStore
>
> Changes: https://git.openjdk.org/jdk/pull/12930/files
>   Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12930&range=00
>    Issue: https://bugs.openjdk.org/browse/JDK-8303832
>    Stats: 8 lines in 1 file changed: 0 ins; 5 del; 3 mod
>    Patch: https://git.openjdk.org/jdk/pull/12930.diff
>    Fetch: git fetch https://git.openjdk.org/jdk pull/12930/head:pull/12930
>
> PR: https://git.openjdk.org/jdk/pull/12930

Perhaps updating the various Object assignments to be somewhat more 
typed as well would be helpful?   E.g.

private static interface Entry {  Instant getInstant(); } // or maybe 
abstract?  All "Date" objects end up as java.time.Instant

private static final class SecretKeyEntry implements Entry { ... }  // 
and the same for PrivateKeyEntry and SecretKeyEntry


private Hashtable<String, Entry> = new Hashtable<>();

Entry entry = entries.get(alias.toLowerCase(Locale.ENGLISH));

Etc.


Last note - perhaps modify the internal storage of the creation date 
from java.util.Date to a java.time.Instant?

createInstant = Instant.now().truncatedTo(ChronoUnit.SECONDS);

That makes the core of engineGetCreationDate to be something like:

return Date.from (entry.getInstant());  // Instant is immutable, Date is 
not.