PS2 | WebSocekt 2

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.inject.Inject;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

/**
 * @ServerEndpoint gives the relative name for the end point
 * This will be accessed via ws://localhost:8080/EchoChamber/echo
 * Where "localhost" is the address of the host,
 * "EchoChamber" is the name of the package
 * and "echo" is the address to access this class from the server
 */
@ServerEndpoint("/echo")
public class EchoServer {
    /**
     * @OnOpen allows us to intercept the creation of a new session.
     * The session class allows us to send data to the user.
     * In the method onOpen, we'll let the user know that the handshake was
     * successful.
     */
    @OnOpen
    public void onOpen(Session session){
        System.out.println(session.getId() + " has opened a connection");
        try {
            session.getBasicRemote().sendText("Connection Established");
            SessionHandler.addSession(session);
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    /**
     * When a user sends a message to the server, this method will intercept the message
     * and allow us to react to it. For now the message is read as a String.
     */
    @OnMessage
    public void onMessage(String message, Session session){
        SessionHandler.sendToallConnectedSessions(message);
    }

    /**
     * The user closes the connection.
     *
     * Note: you can't send messages to the client from this method
     */
    @OnClose
    public void onClose(Session session){
        System.out.println("Session " +session.getId()+" has ended");
        SessionHandler.removeSession(session);

    }

    @OnError
    public void onError(Throwable error) {
        Logger.getLogger(EchoServer.class.getName()).log(Level.SEVERE, null, error);
    }
}








import java.io.IOException;
import java.util.HashSet;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.websocket.Session;

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author student_10
 */
public class SessionHandler {
    private static final Set<Session> sessions = new HashSet<>();

    public static void addSession(Session session){
        sessions.add(session);
    }

    public static void removeSession(Session session){
        sessions.remove(session);
    }

    public static void sendToSession(Session session, String message){
       try {
            session.getBasicRemote().sendText(message.toString());
        } catch (IOException ex) {
            sessions.remove(session);
            Logger.getLogger(SessionHandler.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public static void sendToallConnectedSessions(String message){
         for (Session session : sessions) {
            sendToSession(session, message);
        }
    }
}