Add method to asynchronously send messages of unknown length

[glassfishrobot]

At the moment RemoteEndpoint.Async only has methods that send messages of a known length that are fully buffered in memory. It would be good if this could be extended to also include some way of sending messages piecemeal.

At the moment this can be accomplished using RemoteEndpoint.Basic using the stream and writer, however this requires the use of blocking IO.

As a suggestion as to what this API could look like maybe something like:

void sendPartialText(String message, PartialCallback back);

interface PartialCallback {

   void onWritePossible(TextSender sender);

}

interface TextSender {
  boolean isReady();
  void send(String text, boolean last);
}

[glassfishrobot]

• Issue Imported From: https://github.com/javaee/websocket-spec/issues/225
• Original Issue Raised By:@glassfishrobot
• Original Issue Assigned To: @pavelbucek

[glassfishrobot]

@glassfishrobot Commented Reported by stuartdouglas

[glassfishrobot]

@glassfishrobot Commented This issue was imported from java.net JIRA WEBSOCKET_SPEC-225