EchoWebSocketEndPoint.java

package org.vivek.j2ee.websockets.server;
import javax.websocket.CloseReason;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
@ServerEndpoint(value = "/echo") public class EchoWebSocketEndPoint {
 private static List < Session > connectedSessions = new LinkedList < > ();
 @OnMessage public void getMessage(final String message, final Session session) {
  if (!connectedSessions.contains(session)) {
   connectedSessions.add(session);
   broadcastToAll("user" + session.getId() + " joined");
  } else {
   broadcastToAll("user" + session.getId() + " says > " + message);
  }
 }
 private void broadcastToAll(final String s) {
  for (Session session: connectedSessions) {
   try {
    session.getBasicRemote().sendText(s);
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }
 @OnClose public void closeConnectionHandler(Session session, CloseReason closeReason) {
  connectedSessions.remove(session);
  broadcastToAll("user" + session.getId() + " quit");
 }
}