WebSocketServlet.java

package com.pegaxchange.java.web;

import java.io.IOException;
import java.util.List;
import java.util.Map;

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("/endpoint")
public class WebSocketServlet {
    
    @OnOpen
    public void onOpen(Session session) {
        System.out.println( "onOpen::" + session.getId() );        
    }
    
    @OnClose
    public void onClose(Session session) {
        System.out.println( "onClose::" +  session.getId() );
    }
    
    @OnMessage
    public void onMessage(String message, Session session) {
        System.out.println("onMessage::From=" + session.getId() + " Message=" + message);
        try {
            session.getBasicRemote().sendText("Hello Client " + session.getId() + "!");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    @OnError
    public void onError(Throwable t) {
        System.out.println("onError::" + t.getMessage());
    }
}