How to get active websocket sessions in tomcat programatically?

Question

I am running tomcat 8 to terminate websocket connections. I want to get all active websocket sessions say for an endpoint. I know that if you have one session object you can call getOpenSessions() to get all sessions, but the point is that I do not have access to a session object from where I need to get all sessions in code.

Answer 1

Wow, no answers after nearly a year! I stumbled across this while searching for some clues to an issue I'm having on Tomcat 8 with getOpenSessions(). For my problem, I ended up doing the below, which would also solve this issue. In general, just have a static map that you populate in open and remove from in close:

@ServerEndpoint(value="/msg/{owner}", encoders=MessageEncoder.class, decoders=MessageEncoder.class)
public class WebSocketListener {
    private static final Logger logger = LoggerFactory.getLogger(WebSocketListener.class);
    private static Map<String, Session> sessions = new HashMap<String, Session>();

    public WebSocketListener() {
        System.out.println("created");
    }

    @OnOpen
    public void open(Session session, @PathParam("owner") String owner) {
        System.out.println("open "+owner);
        sessions.put(session.getId(), session);
        session.getUserProperties().put("owner", owner);
        System.out.println("open");
        if (session.getUserPrincipal() != null) {
            session.getUserProperties().put("owner", owner);
        }
        else {
            try {
                session.close(new CloseReason(CloseReason.CloseCodes.CANNOT_ACCEPT, "Not authorized"));
            } catch (IOException e) {
            }
        }
    }

    @OnClose
    public void close(Session session) {
        System.out.println("close");
        sessions.remove(session.getId());
    }

    @OnError
    public void onError(Throwable error) {
        logger.error("",error);
    }

    @OnMessage
    public void onMessage(final Session session, final Message message) {
        System.out.println("onMessage");
        String owner = (String)session.getUserProperties().get("owner");
        Long appId = message.getAppId();
        for (Session s:sessions.values()) {
            System.out.println(s);
            if (s.isOpen() && (message.isEcho() || s != session) && owner.equals(s.getUserProperties().get("owner")) && (appId == null || appId.equals(s.getUserProperties().get("appId")))) {
                s.getAsyncRemote().sendObject(message);
            }
        }
    }

}