WebSockets: The Current State of the Most Valuable HTML5 API for Java Developers

If I'd have to vote for the most important HTML5 new API, I'd select WebSockets. This is a new protocol that allows full duplex communication as opposed to request-response HTTP model. WebSockets API is included in the Java EE 7 (JSR 356).
HTML5 specification includes WebSockets, a new communication protocol for the Web. It's becoming the best choice for building real-time Web applications. This presentation is an overview of the servers and frameworks that support WebSockets. You'll see some use cases where WebSockets shine. We'll also discuss various approaches for the server- and client-side implementations of WebSockets that can be used in the Web applications today.

Example application could be found on github

https://github.com/gAmUssA/websockets-demos

Transcript

1. WEB SOCKETS CURRENT STATE FOR JAVA DEVELOPERS
2. CURRENT STATE FOR JAVA DEVELOPERS Web SOCKETS VIKTOR GAMOV PRESENTED BY
3. WEB SOCKETS BIT OF HISTORY MEET THE WEBSOCKETS WEBSOCKETS IN ACTION Q & A SESSION AGENDA ?
4. “LEGACY” WEB POLLING LONG-POLLING STEAMING OPTIONS FOR “REALTIME” WEB Browser sends a request to the server and the server keeps the request open for a set period of time. If a notification is received within that period, a response containing the message is sent to the client. If a notification is not received within the set time period, the server sends a response to terminate the open request. Browser sends a complete request, but the server sends and maintains an open response that is continuously updated and kept open indefinitely (or for a set period of time) Browser sends HTTP requests at regular intervals and immediately receives a response. However, real- time data is often not that predictable, making unnecessary requests inevitable and as a result, many connections are opened and closed needlessly in low- message-rate situations
5. WHAT IS WEBSOCKET “Reducing kilobytes of data to 2 bytes... and reducing latency from 150ms to 50 ms is far more than marginal. In fact, these two factors alone are enough to make WebSocket seriously interesting...” www.ietf.org/mail-archive/web/hybi/current/msg00784.html
6. WEB SOCKET STANDARD PROTOCOL CLIENT-SIDE API SERVER-SIDE API WHAT IS WEBSOCKETS? HTML5 specification introduces WebSocket client side object. No plugin required. True real-time server updates. Expected large penetration in Java world with upcoming JavaEE 7 spec and JSR-356 Websocket is a standardized technology (described in RFC6455) to support low-overhead bidirectional traffic from your Web browser.
7. 1 2 3 4 SEND UPGRADE REQUEST RECEIVE UPGRADE RESPONSE CHANGE READYSTATE TO OPEN LISTEN MESSAGE EVENT WEBSOCKET HANDSHAKE To Start full-duplex communication client should send UPGRADE request
8. DEMO HANDSHAKE DEMO
10. WEBSOCKET INTERFACE [Constructor(DOMString  url,  optional  (DOMString  or  DOMString[])  protocols)] interface  WebSocket  :  EventTarget  {    readonly  attribute  DOMString  url;    //  ready  state    const  unsigned  short  CONNECTING  =  0;    const  unsigned  short  OPEN  =  1;    const  unsigned  short  CLOSING  =  2;    const  unsigned  short  CLOSED  =  3;    readonly  attribute  unsigned  short  readyState;    readonly  attribute  unsigned  long  bufferedAmount;    //  networking    [TreatNonCallableAsNull]  attribute  Function?  onopen;    [TreatNonCallableAsNull]  attribute  Function?  onerror;    [TreatNonCallableAsNull]  attribute  Function?  onclose;    readonly  attribute  DOMString  extensions;    readonly  attribute  DOMString  protocol;    void  close([Clamp]  optional  unsigned  short  code,  optional  DOMString  reason);    //  messaging    [TreatNonCallableAsNull]  attribute  Function?  onmessage;                      attribute  DOMString  binaryType;    void  send(DOMString  data);    void  send(ArrayBufferView  data);    void  send(Blob  data); };
11. CLIENT-SIDE WEBSOCKET API var  ws; if  (window.WebSocket)  {        output("WebSocket  supported  in  your  browser");        ws  =  new  WebSocket("ws://www.websockets.org");        //  Set  event  handlers.        ws.onopen  =  function  ()  {                output("onopen");        };        ws.onmessage  =  function  (e)  {                //  e.data  contains  received  string.                output("echo  from  server  :  "  +  e.data);        };        ws.onclose  =  function  ()  {                output("onclose");        };        ws.onerror  =  function  ()  {                output("onerror");        }; } else  {output("WebSocket  not  supported  in  your  browser");}
12. JAVA EE 7 SERVER-SIDE API package  org.javaee.glassfishwebsocket; import  org.glassfish.websocket.api.annotations.WebSocket; import  org.glassfish.websocket.api.annotations.WebSocketMessage; @WebSocket(path  =  "/echo") public  class  EchoBean  {        @WebSocketMessage        public  String  echo(String  message)  {                System.out.println("#####################  Message  received");                return  message  +  "  (from  your  server)";        } }
13. TOMCAT 7.0.29 SERVER-SIDE API SHOW THE CODE Not enough room for code in this slide ;-)
14. PROGRAMMING WEBSOCKETS Client-side frameworks ✦jquery.socket.js ✦https://github.com/flowersinthesand/jquery-socket/wiki ✦atmosphere.js ✦https://github.com/Atmosphere/atmosphere/wiki/jQuery.atmosphere.js-API ✦socket.io
15. WEBSOCKET SUPPORT JAVA-based Web servers with native support. The WebServer has API for WebSocket ✦Netty 3.3.x ✦Jetty 7.x, 8.x ✦Glassfish 3.1.2 ✦Tomcat 7.0.27
16. WHAT SHOULD WE DO? WE CAN DO IT!
17. WHAT IS ATMOSPHERE Atmosphere https://github.com/Atmosphere/atmosphere/ ✦portable framework for ✦long-polling ✦Streaming ✦Server-Send Events ✦WebSockets ✦can auto select best transport ✦abstracting from actual underlying container mechanism
18. ? THINKING ABOUT USE CASES
19. OUR CLIENTS USE CASE WebSockets really shine with following applications: ✦Live trading/sports ticker ✦Controlling medical equipment over the web ✦Chat applications ✦Multiplayer online games ✦Realtime updating social streams
20. BUNCH OF USEFUL LINKS ✦http://www.w3.org/TR/websockets/ MUST! ✦http://tools.ietf.org/html/rfc6455 MUST! ✦http://tomcat.apache.org/tomcat-7.0-doc/web-socket-howto.html ✦http://websocket-sdk.java.net/Introduction.html ✦https://github.com/Atmosphere/atmosphere/wiki/Supported- WebServers-and-Browsers ✦http://autobahn.ws/testsuite
21. Q AND A Q& A Put your questions
22. WWW.FARATASYSTEMS.COM INFO@FARATASYSTEMS.COM CONTACT US
23. TWITTER WWW.TWITTER.COM/GAMUSSA GITHUB WWW.GITHUB.COM/GAMUSSA FIND ME
24. THANK YOU FOR YOUR ATTENTION HTTP://WWW.FARATASYSTEMS.COM THANK YOU