1. 2013 © Trivadis
BASEL BERN LAUSANNE ZÜRICH DÜSSELDORF FRANKFURT A.M. FREIBURG I.BR. HAMBURG MÜNCHEN STUTTGART WIEN
JUG Münster Scalable enterprise
applications with JEE7
and beyond
Andy Moncsek
17. April 2013
18.07.2013
JEE to the Max
1

2. 2013 © Trivadis
BASEL BERN LAUSANNE ZÜRICH DÜSSELDORF FRANKFURT A.M. FREIBURG I.BR. HAMBURG MÜNCHEN STUTTGART WIEN
Andy Moncsek
Consultant for Application Devlopment (Zürich)
Trainer for JavaEE Assembly & Deployment
Contacts: Andy.Moncsek@Trivadis.com
Twitter: @AndyAHCP

3. 2013 © Trivadis
AGENDA
1. Motivation
2. Server Sent Events
3. WebSocket (JSR-356)
4. SSE & WebSockets in Enterprise
 Security
 Loadbalancing / Failover
5. (short) JEE 7 project overview
18.07.2013
JEE to the Max
3

4. 2013 © Trivadis
Motivation
18.07.2013
JEE to the Max
4
JEE 7
what’s new?

5. 2013 © Trivadis
Motivation
18.07.2013
JEE to the Max
5
state: function() { return state; }, always: function() { deferred.done(
arguments ).fail( arguments ); return this; }, then: function( /*
fnDone, fnFail, fnProgress */ ) { var fns = arguments; return
jQuery.Deferred(function( newDefer ) { jQuery.each( tuples,
function( i, tuple ) { var action = tuple[ 0 ], fn = jQuery.isFunction(
fns[ i ] ) && fns[ i ]; // deferred[ done | fail | progress ] for
forwarding actions to newDefer deferred[ tuple[1] ](function() { var
returned = fn && fn.apply( this, arguments ); if ( returned &&
jQuery.isFunction( returned.promise ) ) { returned.promise() .done(
newDefer.resolve ) .fail( newDefer.reject ) .progress(
newDefer.notify ); } else { newDefer[ action + "With" ]( this ===
promise ? newDefer.promise() : this, fn ? [ returned ] : arguments );
} }); }); fns = null; }).promise(); },

6. 2013 © Trivadis
Focus
18.07.2013
JEE to the Max
6
Java

7. 2013 © Trivadis
Server Sent Events
18.07.2013
JEE to the Max
7

8. 2013 © Trivadis
Server Sent Events - Overview
• push from server to client
• SSE EventSource API part
of HTML5
• Part of Jersey 2 API’s (JAX-RS)
• JMS – Topic(Light)?
18.07.2013
JEE to the Max
8

9. 2013 © Trivadis
SSE
DEMO
https://bitbucket.org/amoncsek/jeemax
18.07.2013
JEE to the Max
9

10. 2013 © Trivadis
SSE
18.07.2013
JEE to the Max
10
TimerBean:
write(new Event(«custom»,data));
Handle:
void onEvent(InboundEvent e)
@Path(«myEventStream»)
Subscibe once:
new EventSource(http://.../myEventStream)

11. 2013 © Trivadis
SSE- ServerSide
• Subscribe an Event Stream
@GET
@Produces(SseFeature.SERVER_SENT_EVENTS)
public EventOutput getEventStream() {
return new EventOutput();
}
• Put Message to EventOutput
EventOutput.write(
new OutboundEvent("custom-message“, message))
18.07.2013
JEE to the Max
11

12. 2013 © Trivadis
SSE– ClientSide (Jersey 2 API’s)
• Client API
Client client = ClientBuilder.newClient();
WebTarget webTarget = client.target(TARGET_URI);
• EventSource API
new EventSource(webTarget) {
public void onEvent(InboundEvent event) {…}
}
18.07.2013
JEE to the Max
12

13. 2013 © Trivadis
SSE– Best Practice
• Client: EventSource.close() also closes the Server: EventOutput!
• Use SseBroadcaster to broadcast messages to EventOutput
• Register: SseBroadcaster.add(EventOutput)
• Broadcast: SseBroadcaster.broadcast(OutboundEvent)
• Use Server: OutboundEvent.name(«myMessage») to filter
messages (like JMS message-property/selector)
• Client: InboundEvent.getName().equals(«myMessage»)
18.07.2013
JEE to the Max
13

14. 2013 © Trivadis
SSE
Any questions?
18.07.2013
JEE to the Max
14

15. 2013 © Trivadis
WebSocket (JSR-356)
18.07.2013
JEE to the Max
15

16. 2013 © Trivadis
WebSocket - Overview
18.07.2013
JEE to the Max
16
• Full duplex communication in either
direction
• Java API for Server- and Client-Side
(JEE7)
• Programmatic and annotation-based
endpoints
• Support for Encoder/Decoder to map
message to Java objects
• Support for @PathParam

17. 2013 © Trivadis
WebSocket(JSR 356) - Overview
18.07.2013
JEE to the Max
17
• Part of Glassfish 4
• Tyrus project:
• reference implementation for JSR 356 WebSocket API for Java
• http://java.net/projects/tyrus

18. 2013 © Trivadis
WebSocket
18.07.2013
JEE to the Max
18
@ServerEndpoint("/bookings") @ClientEndpoint
Session Session
messages
Connect

19. 2013 © Trivadis
WebSocket – ServerEndpoint (by annotation)
18.07.2013
JEE to the Max
19
• Creating Server Endpoints with annotation
@ServerEndpoint("/bookings")
public class BookingEndpoint {
@OnOpen
public void init(Session s) {}
@OnClose
…
@OnError
…
@OnMessage
public void handleMessage(Message m, Session s) {}
}

20. 2013 © Trivadis
WebSocket – ServerEndpoint (programmatic)
18.07.2013
JEE to the Max
20
• Creating Server Endpoints programmatic
public class BookingEndpoint extends Endpoint {
@Override
public void onOpen(Session s, EndpointConfig ec) {
s.addMessageHandler(new MessageHandler() {
@Override
public void onMessage(String text) {…}
});
}
}

21. 2013 © Trivadis
WebSocket - ServerEndpoint
18.07.2013
JEE to the Max
21
• Configuring a programmatic Endpoint (WebSocket runtime scans the
WAR)
public class WSAppConfig implements ServerApplicationConfig
{
public Set<ServerEndpointConfig> getEndpointConfigs(Set
set) {
add(ServerEndpointConfig.Builder
.create(BookingEndpoint.class, "/bookings")
.build());
}
}

22. 2013 © Trivadis
WebSocket - ClientEndpoint
18.07.2013
JEE to the Max
22
• Creating Client Endpoints with annotation
@ClientEndpoint
public class Booking {
@OnOpen
…
@OnClose
…
@OnError
…
@OnMessage
…
}

23. 2013 © Trivadis
WebSocket - ClientEndpoint
18.07.2013
JEE to the Max
• Creating programmatic Client Endpoint
public class Booking extends Endpoint {
@Override
public void onOpen(Session s, EndpointConfig c) {
s.addMessageHandler(…);
}
}
23

24. 2013 © Trivadis
WebSocket - ClientEndpoint
18.07.2013
JEE to the Max
24
• Configure a Client Endpoint
ClientManager client = ClientManager.createClient();
ClientEndpointConfig config =
ClientEndpointConfig.Builder.create();
client.connectToServer(new Booking(),config
URI.create(“ws://host/bookings“));
Or
client.connectToServer(Booking.class,config
URI.create(“ws://host/bookings“));

25. 2013 © Trivadis
WebSocket Encoder/Decoder
• Native Message-format is:
• Text
• Binary
• Pong (check connection)
• Encoders:
• Encode message from Java Object to Binary / Text
• Decoders
• Decode message from Binary / Text to Java Object
18.07.2013
JEE to the Max
25

26. 2013 © Trivadis
WebSocket Encoder
public class MEnc implements Encoder.Binary<Message> {
@Override
public ByteBuffer encode(Message m) throws EncodeException {
return ByteBuffer.wrap(SerializationUtils.serialize(message));
}
}
Register Encoders
Client: @ClientEndpoint(encoders = {Menc.class, Menc2.class})
Server: @ServerEndpoint(encoders = {Menc.class, Menc2.class})
18.07.2013
JEE to the Max
26

27. 2013 © Trivadis
WebSocket Decoder
public class MessageDecoder implements Decoder.Binary<Message> {
public Message decode(ByteBuffer b) throws DecodeException {
return (Message) SerializationUtils.deserialize(b.array()); }
public boolean willDecode(ByteBuffer b) {
return true }
}
Register Decoders
Client: @ClientEndpoint(decoders = {MessageDecoder.class, Dec.class})
Server: @ServerEndpoint(decoders = {MessageDecoder.class, Dec.class})
18.07.2013
JEE to the Max
27

28. 2013 © Trivadis
WebSocket @PathParam
• Annotate one or more parameters on:
• @OnMessage, @OnError, @OnClose, @OnOpen
@ServerEndpoint("/bookings/{id}")
public class BookingEndpoint {
@OnMessage
public void handle(@PathParam(“id”) String id,
Message m, Session s) {}
}
18.07.2013
JEE to the Max
28

29. 2013 © Trivadis
WebSockets – sending messages
• BUT… how to send messages?
• BasicRemote: blocking until message has been transmitted
• session.getBasicRemote().sendObject(message);
• AsyncRemote: fire and forget
• Future<Void> v =
session.getAsyncRemote().sendObject(message);
• Progress may be tracked using the Future Object
18.07.2013
JEE to the Max
29

30. 2013 © Trivadis
WebSockets – Broadcasting messages
• interaction with other Sessions
• Identify Sessions by ID
• Only Sessions in same Endpoint are accessible
• Sessions only accessible trough Session:
• session.getOpenSessions()
18.07.2013
JEE to the Max
30

31. 2013 © Trivadis
Best Practice
• No automatic reconnection:
• Use OnError to reconnect
• Use Session.getUserProperties() to store additional informations
• Server Endpoitns have full support for CDI and @Inject
• Endpoint can be @Singleton / @Stateless… but requirement was
removed from spec!
18.07.2013
JEE to the Max
31

32. 2013 © Trivadis
Best Practice
• One handling method per type!:
• Each websocket endpoint may only have one message handling
method for each of the native websocket message formats.
• Solution: inherence, Enums,…
18.07.2013
JEE to the Max
32
@OnMessage
public void onAddUser(AddUser user) {
}
@OnMessage
public void onMessage(Message m) {
}
@OnMessage
public void onChatMessage(Message chatMessage) {
switch (chatMessage.getType()){
case MESSAGE:
break;
case ADD_USER:
break;
}
}

33. 2013 © Trivadis
WebSockets
Any questions?
18.07.2013
JEE to the Max
33

34. 2013 © Trivadis
SSE / WebSockets in Enterprise
SSE / WebSockets in Enterprise
Securtity
18.07.2013
JEE to the Max
34

35. 2013 © Trivadis
Security – Jersey 2 SSE
• Basic authentication - Jersey 2 way:
Client client = ClientBuilder.newBuilder().build();
WebTarget webTarget = client.target(restURL);
webTarget.register(new HttpBasicAuthFilter(user, pwd));
• Easy SSL konfigurations
SslConfigurator sslConfig =
SslConfigurator.newInstance()
.keyStoreFile("keystore.jks")
.keyPassword("asdfgh")
.scurityProtocol("SSL");
18.07.2013
JEE to the Max
35

36. 2013 © Trivadis
Security – WebSocket (Tyrus API)
• Initial handshake over HTTP/HTTPS (ws:// | wss://)
• Session.getPrincipal() available
BUT….
NO Client API for authentication!
18.07.2013
JEE to the Max
36

37. 2013 © Trivadis
Security – WebSocket (Tyrus API)
• Authentication is nevertheless possible (request properties)
c = new ClientEndpointConfig.Configurator() {
public void beforeRequest(Map<String, List<String>> headers)
{
headers.put("Authorization",
Arrays.asList("Basic " + BASE64Enc.encode(encPwd))));
}
};
config = ClientEndpointConfig.Builder.
create().
configurator(c).build();
client.connectToServer(CEndpoint.class, config, “ws://…/endpoint");
18.07.2013
JEE to the Max
37

38. 2013 © Trivadis
Loadbalancing
18.07.2013
JEE to the Max
38
Loadbalancing

39. 2013 © Trivadis
Loadbalancing - SSE
• Works with mod_proxy / mod_jk
• Problem: notification of EventOutput on each Cluster-Node (Broadcast)
• Workaround: bypass the LB and notify the nodes
• Duplicate messages to other nodes
• Use JMS to notify all nodes in cluster
18.07.2013
JEE to the Max
39

40. 2013 © Trivadis
BASEL BERN LAUSANNE ZÜRICH DÜSSELDORF FRANKFURT A.M. FREIBURG I.BR. HAMBURG MÜNCHEN STUTTGART WIEN
18.07.2013
JEE to the Max
‹#›

41. 2013 © Trivadis
Failover
18.07.2013
JEE to the Max
41
Failover

42. 2013 © Trivadis
Failover SSE
• On connection drop:
• Error event
• Try to reconnect
• default wait before trying to reconnect is 3 seconds
18.07.2013
JEE to the Max
42

43. 2013 © Trivadis
Failover WebSockets
• No Session replication available in current (Tyrus) version!
• Use @OnError to reconnect on failure
• Do NOT use properties on Session
• Problem: message broadcasting
• Set LB weight 100 to one Node
• Ensure that all sessions on one Node
• Duplicate messages to other nodes
18.07.2013
JEE to the Max
43

44. 2013 © Trivadis
SSE vs. WebSockets
• send/receive data from client
• provide true real-time
updates
• require servers that
understand the protocol
• Can identify peers (by ID)
18.07.2013
JEE to the Max
44
• push data to client
• can be configured to provide
close to real-time
• sent over traditional HTTP, so
no modification is required
• Can identify events (by ID)
WebSocket Server-Sent Events

45. 2013 © Trivadis
Conclusion
Is it Enterprise Ready?
SSE – Yes
WebSocket - Nearly
18.07.2013
JEE to the Max
45

46. 2013 © Trivadis
JEE 7 project overview
18.07.2013
JEE to the Max
46
• Client API - using builder pattern
• asynchronous request processing
Future<String> future =
client.target("http://...").pathParam("", "")
.request("text/plain").async().get(..);
[4]

47. 2013 © Trivadis
JEE 7 project overview
18.07.2013
JEE to the Max
47
Example project with MongoDB
replication in Bitbucket (see Demos)
[4]

48. 2013 © Trivadis
JEE 7 project overview
18.07.2013
JEE to the Max
48
@Resource(lookup = "jms/connectionFactory")
ConnectionFactory connectionFactory;
@Resource(lookup="jms/inboundQueue")
Queue inboundQueue;
public void sendMessageNew (String payload) {
try (JMSContext context = connectionFactory.createContext();)
{
context.send(inboundQueue,payload);
}
}
[4]

49. 2013 © Trivadis
JEE 7 project overview
18.07.2013
JEE to the Max
49
@Resource(name = "concurrent/myExecutor")
ManagedExecutorService executor;
executor.execute(new MyRunnableTask(2));
[4]

50. 2013 © Trivadis
BASEL BERN LAUSANNE ZÜRICH DÜSSELDORF FRANKFURT A.M. FREIBURG I.BR. HAMBURG MÜNCHEN STUTTGART WIEN
VIELEN DANK.
Andy Moncsek
Andy.Moncsek@Trivadis.com
www.trivadis.com
18.07.2013
JEE to the Max
50

51. 2013 © Trivadis
Appendix
1. Wallpaper: http://bensow.deviantart.com/art/Wallpaper-Under-Construction-
252593627
2. http://de.slideshare.net/MasoudKalali/server-sent-events-async-servlet-web-
sockets-and-json-born-to-work-together
3. Tyrus Project: http://java.net/projects/tyrus
4. Jersey 2: http://jersey.java.net/jersey20.html
5. JacpFX: https://code.google.com/p/jacp/
6. GlassFish 4 downloads: http://glassfish.java.net/public/downloadsindex.html
7. [3] http://blog.exceliance.fr/2012/11/07/websockets-load-balancing-with-
haproxy/
8. [4] http://de.slideshare.net/arungupta1/the-java-ee-7-platform-productivity-
html5-16124993
9. http://download.oracle.com/otndocs/jcp/websocket-1_0-pfd-spec/index.html
18.07.2013
JEE to the Max
51