RFR 8234147 : Avoid looking up standard charsets in core libraries

[Alan Bateman]

On 27/11/2019 04:39, Ivan Gerasimov wrote:
> Hello!
>
> It is a cleanup fix with mostly two kinds of changes:
> - when a standard charset is specified by its name, use a 
> preinitialized Charset constant instead,
> - replace the usage of StandardCharset.* constants with their 
> sun.nio.cs.* equivalents to avoid accidental early initialization of 
> rarely-used charsets.
>
> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8234147
> WEBREV: http://cr.openjdk.java.net/~igerasim/8234147/00/webrev/
>
> I also had to modify one regression test that relied on a private 
> auxiliary method, which was removed with the fix.
>
> Mach5 control build looks green.
>
> Would you please help review the fix?
The motivation is okay and most of the changes are okay but it does 
create a needless dependency on sun.nio.* classes in places that are 
unlikely (or impossible) to use during early startup. I think the change 
to the JDBC CachedRow implementation, prefs, and the jdk.net.httpserver 
module should be dropped as want fewer classes outside of java.base 
depending on java.base internals, not more. I also wonder about the 
NTLM, XML properties and a few more that shouldn't be dependency on 
sun.nio.* classes if possible.

Minot nit but if this is pushed then it would be good to keep the 
imports consistent with the existing style where you can, e.g. I see 
several files where the import sun.nio.* is put at the top of source 
files that already group imports of JDK internal classes together 
further down.

Mandy might want to comment on TrySetAccessibleTest. If I'm not mistaken 
it should say "non-exported" rather than "exported". Also I think we 
want this test to have a dependency on a few JDK internal and private 
methods as possible as it's a maintenance issue to keep it up to date 
(as you've experienced here with the removal of Perf.getBytes).

-Alan