RFR JDK-8156742: Miscellaneous WebSocket API improvements

[Pavel Rappo]

> On 2 Jun 2016, at 13:00, Simone Bordet <simone.bordet at gmail.com> wrote:
> 
> Furthermore, I'm not convinced there should be a parameterless sendClose().
> The WebSocket protocol itself *mandates* that the Close message must
> have a code

Regardless of your API proposal, where did you find that in the RFC?
Here's what I see:

7.4.  Status Codes


   When closing an established connection (e.g., when sending a Close
   frame, after the opening handshake has completed), an endpoint MAY
   indicate a reason for closure.  The interpretation of this reason by
   an endpoint, and the action an endpoint should take given this
   reason, are left undefined by this specification.  This specification
   defines a set of pre-defined status codes and specifies which ranges
   may be used by extensions, frameworks, and end applications. *The
   status code and any associated textual message are optional
   components of a Close frame.*

...

5.5.1.  Close


   The Close frame contains an opcode of 0x8.

   *The Close frame MAY contain a body (the "Application data" portion of
   the frame)* that indicates a reason for closing, such as an endpoint
   shutting down, an endpoint having received a frame too large, or an
   endpoint having received a frame that does not conform to the format
   expected by the endpoint.  If there is a body, the first two bytes of
   the body MUST be a 2-byte unsigned integer...