Websockets using GWT - Best practice

[andymel]

Hi,

I'm currently trying to establish a websocket connection in GWT 2.6 and 2.7 using gwt-ws.

My question:
the Google search points me to the gwt-ws project to implement websocket connections. But the code examples there do not work with the jetty version included in GWT 2.6 and 2.7

Is there a best practice to do it know? Any known code examples you can point me to?

More infos about the problem:
The server (coded as shown at "Getting Started" https://code.google.com/p/gwt-ws/)throws an AbstractMethodExeption.

Here is the full StackTrace

java.lang.AbstractMethodError: de.csenk.gwt.ws.server.jetty.JettyWebSocketConnection.onOpen(Lorg/eclipse/jetty/websocket/WebSocket$Connection;)V
 at org.eclipse.jetty.websocket.WebSocketConnectionRFC6455.onWebSocketOpen(WebSocketConnectionRFC6455.java:425)
 at org.eclipse.jetty.websocket.WebSocketServletConnectionRFC6455.handshake(WebSocketServletConnectionRFC6455.java:60)
 at org.eclipse.jetty.websocket.WebSocketFactory.upgrade(WebSocketFactory.java:323)
 at org.eclipse.jetty.websocket.WebSocketFactory.acceptWebSocket(WebSocketFactory.java:396)
 at org.eclipse.jetty.websocket.WebSocketServlet.service(WebSocketServlet.java:104)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
 at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
 at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:501)
 at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
 at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:557)
 at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
 at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
 at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:428)
 at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
 at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
 at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
 at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
 at org.eclipse.jetty.server.Server.handle(Server.java:370)
 at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
 at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:949)
 at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1011)
 at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644)
 at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
 at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
 at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668)
 at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
 at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
 at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
 at java.lang.Thread.run(Thread.java:744)

Seems like the onOpen() method was added in the WebSocket interface

The implementation de.csenk.gwt.ws.server.jetty.JettyWebSocketConnection seems to implement an older WebSocket interface without onOpen method.

thanks in advance!!
Andy

[oneTETSUO]

On the first view on your stack trace, I've seen, that the sources for the backend is missing . Put the sources of each lib/fw in your buildpath, it should change the stack trace, at least