Ping pong mechanism works.

build.gradle

@@ -27,5 +27,8 @@ dependencies {
 	compile('org.springframework.boot:spring-boot-starter-web')
 	compile('org.springframework.boot:spring-boot-starter-websocket')
 	compile('org.webjars:sockjs-client:0.3.4')
+	compile('org.webjars:bootstrap:3.3.7-1')
+	compile('org.webjars:jquery:3.2.1')
+	compile('org.webjars:bootbox:4.4.0')
 	testCompile('org.springframework.boot:spring-boot-starter-test')
 }

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/configs/WebsocketConfig.java

@@ -1,6 +1,8 @@
 package pl.polgrabiat.websockets.chat.websocketschat.configs;
 
 import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.web.socket.config.annotation.EnableWebSocket;
 import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
 import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
@@ -10,6 +12,8 @@ import javax.inject.Inject;
 
 @Configuration
 @EnableWebSocket
+@EnableScheduling
+@EnableAsync
 public class WebsocketConfig implements WebSocketConfigurer {
 
     @Inject

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/dto/GlobalCtx.java

@@ -53,4 +53,16 @@ public class GlobalCtx {
     public void setUserNameSessions(Map<String, WebSocketSession> userNameSessions) {
         this.userNameSessions = userNameSessions;
     }
+
+    synchronized public void removeSession(WebSocketSession session) {
+        sessions.remove(session);
+        UserCtx userCtx = userSessions.get(session);
+        userSessions.remove(userSessions);
+        userNameSessions.remove(userCtx.getNick());
+    }
+
+    synchronized public void addSession(WebSocketSession session) {
+        sessions.add(session);
+        userSessions.put(session, new UserCtx(session));
+    }
 }

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/dto/UserCtx.java

@@ -2,11 +2,15 @@ package pl.polgrabiat.websockets.chat.websocketschat.dto;
 
 import org.springframework.web.socket.WebSocketSession;
 
+import java.time.LocalDateTime;
+
 public class UserCtx {
     private final WebSocketSession session;
     private String nick;
     private String userName;
     private String realName;
+    private int lastPongNumber;
+    private LocalDateTime lastPongTime;
 
     public UserCtx(WebSocketSession session) {
         this.session = session;
@@ -39,4 +43,20 @@ public class UserCtx {
     public WebSocketSession getSession() {
         return session;
     }
+
+    public int getLastPongNumber() {
+        return lastPongNumber;
+    }
+
+    public void setLastPongNumber(int lastPongNumber) {
+        this.lastPongNumber = lastPongNumber;
+    }
+
+    public LocalDateTime getLastPongTime() {
+        return lastPongTime;
+    }
+
+    public void setLastPongTime(LocalDateTime lastPongTime) {
+        this.lastPongTime = lastPongTime;
+    }
 }

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/handlers/ChatWebsocketHandler.java

@@ -2,27 +2,30 @@ package pl.polgrabiat.websockets.chat.websocketschat.handlers;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
 import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.PongMessage;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.handler.TextWebSocketHandler;
 import pl.polgrabiat.websockets.chat.websocketschat.dto.GlobalCtx;
 import pl.polgrabiat.websockets.chat.websocketschat.dto.UserCtx;
 
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.time.temporal.ChronoUnit;
+import java.util.*;
 
 @Component
 public class ChatWebsocketHandler extends TextWebSocketHandler {
 
     private static final Logger lg = LoggerFactory.getLogger(ChatWebsocketHandler.class);
+    private static final long PING_PONG_TIME = 59;
 
-    private Set<WebSocketSession> sessions = new HashSet<>();
     private Map<String, SessionCommandHandler> commandHandlers = new HashMap<>();
     private GlobalCtx globalCtx = new GlobalCtx();
+    private Random rnd = new Random();
 
     public ChatWebsocketHandler() {
         commandHandlers.put("USER", new UserCommandHandler());
@@ -30,20 +33,21 @@ public class ChatWebsocketHandler extends TextWebSocketHandler {
         commandHandlers.put("JOIN", new JoinCommandHandler());
         commandHandlers.put("LEAVE", new LeaveCommandHandler());
         commandHandlers.put("PRIVMSG", new PrivMessageHandler());
+        commandHandlers.put("PONG", new PongMessageHandler());
+        commandHandlers.put("PING", new PingMessageHandler());
     }
 
     @Override
     public void afterConnectionEstablished(WebSocketSession session) throws Exception {
         super.afterConnectionEstablished(session);
-        sessions.add(session);
-        globalCtx.getUserSessions().put(session, new UserCtx(session));
+
+        globalCtx.addSession(session);
     }
 
     @Override
     public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
         super.afterConnectionClosed(session, status);
-        sessions.remove(session);
-        globalCtx.getUserSessions().remove(session);
+        globalCtx.removeSession(session);
     }
 
     @Override
@@ -68,4 +72,38 @@ public class ChatWebsocketHandler extends TextWebSocketHandler {
 
         session.sendMessage(new TextMessage("Invalid command " + payload));
     }
+
+
+    @Scheduled(fixedDelay=60000)
+    public void checkSessionActiveness() {
+        LocalDateTime time = LocalDateTime.now();
+        lg.debug("Checking sessions with set local date time {} ...", time);
+        for (WebSocketSession session: globalCtx.getSessions()) {
+            try {
+                UserCtx userCtx = globalCtx.getUserSessions().get(session);
+                LocalDateTime lastPongTime = userCtx.getLastPongTime();
+                if (lastPongTime != null
+                        && lastPongTime.until(LocalDateTime.now(), ChronoUnit.SECONDS) >= PING_PONG_TIME) {
+                    // drop session
+                    lg.trace("Closing session {}[{}]", session.getId(), session.getRemoteAddress());
+                    session.close();
+                    globalCtx.removeSession(session);
+                    continue;
+                }
+
+                int pongNumber = rnd.nextInt();
+                lg.trace("Sending ping message {} to the session {}[{}]",
+                        pongNumber,
+                        session.getId(),
+                        session.getRemoteAddress());
+
+                session.sendMessage(new TextMessage("PING :" + pongNumber));
+                userCtx.setLastPongNumber(pongNumber);
+
+            } catch (IOException e) {
+                lg.warn("I/O error", e);
+            }
+        }
+    }
+
 }

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/handlers/NickCommandHandler.java

@@ -2,6 +2,7 @@ package pl.polgrabiat.websockets.chat.websocketschat.handlers;
 
 import org.springframework.web.socket.WebSocketSession;
 import pl.polgrabiat.websockets.chat.websocketschat.dto.GlobalCtx;
+import pl.polgrabiat.websockets.chat.websocketschat.dto.UserCtx;
 
 import java.io.IOException;
 import java.util.StringTokenizer;
@@ -17,7 +18,14 @@ public class NickCommandHandler implements SessionCommandHandler {
           return true;
         }
 
-        globalCtx.getUserSessions().get(session).setNick(nick);
+        UserCtx userCtx = globalCtx.getUserSessions().get(session);
+        if (userCtx.getNick() != null) {
+            globalCtx.getUserNameSessions().remove(userCtx.getNick());
+            // removing old mapping for destinations
+        }
+
+        userCtx.setNick(nick);
+        globalCtx.getUserNameSessions().put(nick, session);
 
         return true;
     }

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/handlers/PingMessageHandler.java

@@ -0,0 +1,14 @@
+package pl.polgrabiat.websockets.chat.websocketschat.handlers;
+
+import org.springframework.web.socket.WebSocketSession;
+import pl.polgrabiat.websockets.chat.websocketschat.dto.GlobalCtx;
+
+import java.io.IOException;
+
+public class PingMessageHandler implements SessionCommandHandler {
+    @Override
+    public boolean handleCommand(GlobalCtx globalCtx, WebSocketSession session, String payload, String command, String data) throws IOException {
+        sendMessage(session,globalCtx,403, "MSG PING message is not accepted from the client-side");
+        return true;
+    }
+}

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/handlers/PongMessageHandler.java

@@ -0,0 +1,43 @@
+package pl.polgrabiat.websockets.chat.websocketschat.handlers;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.socket.WebSocketSession;
+import pl.polgrabiat.websockets.chat.websocketschat.dto.GlobalCtx;
+import pl.polgrabiat.websockets.chat.websocketschat.dto.UserCtx;
+
+import java.io.IOException;
+import java.time.LocalDateTime;
+import java.util.StringTokenizer;
+
+public class PongMessageHandler implements SessionCommandHandler {
+
+
+    private static final Logger lg = LoggerFactory.getLogger(PongMessageHandler.class);
+
+    @Override
+    public boolean handleCommand(GlobalCtx globalCtx, WebSocketSession session, String payload, String command, String data) throws IOException {
+        UserCtx userCtx = globalCtx.getUserSessions().get(session);
+        if (userCtx == null) {
+            lg.error("We lost an user context - dropping session, sorry...");
+            globalCtx.removeSession(session);
+            return true;
+        }
+
+        StringTokenizer tokenizer = new StringTokenizer(data);
+        String pongValue = tokenizer.nextToken(":");
+
+        lg.debug("Got pong value: {} for {}", pongValue, session);
+        try {
+            int pongVal = Integer.parseInt(pongValue);
+            if (userCtx.getLastPongNumber() == pongVal) {
+                userCtx.setLastPongTime(LocalDateTime.now());
+            }
+        } catch (NumberFormatException e) {
+            lg.debug("Invalid format of pong message. Dropping session", e);
+            globalCtx.removeSession(session);
+        }
+
+        return true;
+    }
+}

src/main/java/pl/polgrabiat/websockets/chat/websocketschat/handlers/UserCommandHandler.java

@@ -1,5 +1,7 @@
 package pl.polgrabiat.websockets.chat.websocketschat.handlers;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.web.socket.WebSocketSession;
 import pl.polgrabiat.websockets.chat.websocketschat.dto.GlobalCtx;
 import pl.polgrabiat.websockets.chat.websocketschat.dto.UserCtx;
@@ -8,6 +10,9 @@ import java.io.IOException;
 import java.util.StringTokenizer;
 
 public class UserCommandHandler implements SessionCommandHandler {
+
+    private static final Logger lg = LoggerFactory.getLogger(UserCommandHandler.class);
+
     @Override
     public boolean handleCommand(GlobalCtx globalCtx, WebSocketSession session, String payload, String command, String data) throws IOException {
         StringTokenizer tokenizer = new StringTokenizer(data," ");
@@ -23,12 +28,15 @@ public class UserCommandHandler implements SessionCommandHandler {
         }
 
         String realName = tokenizer.nextToken(":");
-        UserCtx userCtx = globalCtx.getUserSessions().get(session.getId());
 
-        String nick = userCtx.getNick();
-        if (nick == null || "".equals(nick)) {
+        UserCtx userCtx = globalCtx.getUserSessions().get(session);
 
+        if (userCtx == null) {
+            sendMessage(session, globalCtx, 403,
+                    "MSG you nead to select the nick");
+            return true;
         }
+
         userCtx.setUserName(userName);
         userCtx.setRealName(realName);
 

src/main/resources/logback.xml

@@ -0,0 +1,18 @@
+<configuration>
+
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <!-- encoders are assigned the type
+             ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <logger name="pl.polgrabiat.websockets"
+            level="TRACE"
+            appender-ref="STDOUT"/>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

src/main/resources/static/IrcClient.js

@@ -0,0 +1,52 @@
+function IrcClient(sockJs, nick, userName, realName) {
+    this.sockJs = sockJs;
+    this.nick = nick;
+    this.userName = userName;
+    this.realName = realName;
+
+    this.sendMsg = function(msg) {
+        console.log("OUT-MSG " + msg);
+        this.sockJs.send(msg);
+    };
+
+    this.sendNickMsg = function() {
+        this.sendMsg("NICK " + this.nick);
+    };
+
+    this.sendUserMsg = function() {
+        this.sendMsg("USER " + this.userName + " 0 * :" + this.realName);
+    };
+
+    this.init = function () {
+        this.sendNickMsg();
+        this.sendUserMsg();
+    };
+
+    var ircClientRef = this;
+
+    this.sockJs.onopen = function () {
+        console.log("Socket opened");
+        ircClientRef.init();
+    };
+
+    this.sockJs.onclose = function () {
+        console.log("Socket closed");
+    };
+
+    this.sendPongMsg = function(nr) {
+        this.sendMsg("PONG :" + nr);
+    };
+
+    this.handlePongMessage = function (payload, data) {
+        console.log("PING message: " + data);
+        this.sendPongMsg(data);
+    };
+
+    this.sockJs.onmessage = function (e) {
+        console.log("Received message: " + e.data);
+        if (e.data.startsWith("PING ")) {
+            ircClientRef.handlePongMessage(e.data, e.data.substr(7));
+        }
+    };
+
+};

src/main/resources/static/index.html

@@ -4,7 +4,13 @@
         <title>SockJS example</title>
         <meta charset="UTF-8" />
         <script type="application/javascript" src="/webjars/sockjs-client/0.3.4/sockjs.js"></script>
+        <script type="application/javascript" src="/webjars/jquery/3.2.1/jquery.js"></script>
+        <script type="application/javascript" src="/webjars/bootstrap/3.3.7-1/js/bootstrap.js"></script>
+        <script type="application/javascript" src="/webjars/bootbox/4.4.0/bootbox.js"></script>
         <script type="application/javascript" src="index.js"></script>
+        <script type="application/javascript" src="IrcClient.js"></script>
+
+        <link type="text/css" rel="stylesheet" href="/webjars/bootstrap/3.3.7-1/css/bootstrap.css"/>
     </head>
     <body>
         <input id="message" type="text" />

src/main/resources/static/index.js

@@ -1,18 +1,29 @@
+window.initSockJs = function () {
+    window.sockJs = null;
+    window.nick = null;
+    bootbox.prompt({
+        title: "Type the nick name for the chat",
+        inputType: 'text',
+        callback: function (result) {
+            console.log("Got nick: " + result);
+            window.nick = result;
+
+            if (window.nick == null || window.nick == undefined || window.nick.length < 1) {
+                console.log("Nick cannot be blank");
+                bootbox.alert("Sorry, nick the cannot be blank", function (res) {
+                    initSockJs();
+                });
+                return;
+            }
+
+            window.sockJs = new SockJS("/chat");
+            window.ircClient = new IrcClient(window.sockJs, window.nick, window.nick, window.nick);
+        }
+    });
+};
+
 window.onload = function () {
-    var sockJs = new SockJS("/chat");
-    sockJs.onopen = function() {
-        console.log("Socket opened");
-        // TODO send a nick message
-        // TODO send the userName and realName message
-    };
-
-    sockJs.onclose = function() {
-        console.log("Socket closed");
-    };
-
-    sockJs.onmessage = function(e) {
-        console.log("Received message: " + e.data);
-    };
+    this.initSockJs();
 
     var messageInput = document.getElementById("message");
     messageInput.onkeyup = function (e) {