-전달되는 메시지를 JSON 문자열로 변환하여 전송한다
var jsObj = 0;
jsObj.sender = userid;
jsObj.receiver = 'jone';
jsObj.msg = 'Hello World';
var jsStr = JSON.stringify(jsObj);
webSocket.send(jsStr);
-서버측
JSONParser parser = new JSONParser();
JSONObject jsObj = parser.parse(message.toString());
String sender = (String)jsObj.get("sender");
String receiver = (String)jsObj.get("receiver");
WebSocketSession session = userMap.get(receiver);
session.sendMessage(message);