RFR: JDK-8304945: StringBuilder and StringBuffer should implement Appendable explicitly

[Alan Bateman]

On Sat, 1 Apr 2023 17:34:37 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> The StringBuilder and StringBuffer classes are Appendable by virtue of from subclasses their non-public superclass AbstractStringBuilder.
> 
> It is slightly clearer to declare StringBuilder and StringBuffer to directly implement Appendable, as they already directly implement the CharSequence interface also implemented by their superclass.
> 
> There are no other interfaces implemented by AbstractStringBuilder other than Appendable and CharSequence.
> 
> Please also review the CSR https://bugs.openjdk.org/browse/JDK-8305408

Right now, the javadoc for SB lists Appendable in the "All Implemented Interfaces" list. With this change it will be shown in the class declaration in the list of "implements" list. Make sense.

-------------

Marked as reviewed by alanb (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13278#pullrequestreview-1368029581