Minor Fixes in spring-websocket

Used Standard Charsets object

Removed unnecessary call to toString

Replaced concatenated strings with text blocks

Removed Arrays.asList call with too few arguments

Fixed Javadoc links

Comment From: sbrannen

Hi @imkulwant,

Thanks for creating your first PR for the Spring Framework.

Aside from some Checkstyle violations and unnecessary Javadoc changes (which I can address for you), I think this PR seems reasonable.

So, would you mind if we reopen and merge this PR?

Comment From: imkulwant

Hi @imkulwant,

Thanks for creating your first PR for the Spring Framework.

Aside from some Checkstyle violations and unnecessary Javadoc changes (which I can address for you), I think this PR seems reasonable.

So, would you mind if we reopen and merge this PR?

Hi @sbrannen

I had closed the PR to fix some test failures. Will fix them and re-open again.

Comment From: sbrannen

These commits have been merged into main and revised in 723e09c1648ff723abcd89e3d25fa1daef015de8.

Thanks