package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.Environment;

import java.net.InetAddress;
import java.net.UnknownHostException;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) throws UnknownHostException {
        ConfigurableApplicationContext application = SpringApplication.run(DemoApplication.class, args);
        Environment env = application.getEnvironment();
        String host = InetAddress.getLocalHost().getHostAddress();
        String port = env.getProperty("server.port");
        System.out.println("[----------------------------------------------------------]");
        System.out.println("聊天室啟動(dòng)成功！點(diǎn)擊進(jìn)入:\t http://" + host + ":" + port);
        System.out.println("[----------------------------------------------------------");
        WebSocketServer.inst().run(53134);
    }

}

package com.example.demo;

import java.util.Objects;

public class User {

    public String id;
    public String nickname;

    public User(String id, String nickname) {
        super();
        this.id = id;
        this.nickname = nickname;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getNickname() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname = nickname;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o)
            return true;
        if (o == null || getClass() != o.getClass())
            return false;
        User user = (User) o;
        return id.equals(user.getId());
    }

    @Override
    public int hashCode() {

        return Objects.hash(id);
    }

    public String getUid() {

        return id;
    }
}

package com.example.demo;

import com.google.gson.Gson;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.ChannelGroupFuture;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.util.concurrent.ImmediateEventExecutor;
import org.springframework.util.StringUtils;

import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public final class SessionGroup {

    private static SessionGroup singleInstance = new SessionGroup();

    // 組的映射
    private ConcurrentHashMap<String, ChannelGroup> groupMap = new ConcurrentHashMap<>();

    public static SessionGroup inst() {
        return singleInstance;
    }

    public void shutdownGracefully() {

        Iterator<ChannelGroup> groupIterator = groupMap.values().iterator();
        while (groupIterator.hasNext()) {
            ChannelGroup group = groupIterator.next();
            group.close();
        }
    }

    public void sendToOthers(Map<String, String> result, SocketSession s) {
        // 獲取組
        ChannelGroup group = groupMap.get(s.getGroup());
        if (null == group) {
            return;
        }
        Gson gson=new Gson();
        String json = gson.toJson(result);
        // 自己發(fā)送的消息不返回給自己
//      Channel channel = s.getChannel();
        // 從組中移除通道
//      group.remove(channel);
        ChannelGroupFuture future = group.writeAndFlush(new TextWebSocketFrame(json));
        future.addListener(f -> {
            System.out.println("完成發(fā)送："+json);
//          group.add(channel);//發(fā)送消息完畢重新添加。

        });
    }

    public void addSession(SocketSession session) {

        String groupName = session.getGroup();
        if (StringUtils.isEmpty(groupName)) {
            // 組為空，直接返回
            return;
        }
        ChannelGroup group = groupMap.get(groupName);
        if (null == group) {
            group = new DefaultChannelGroup(ImmediateEventExecutor.INSTANCE);
            groupMap.put(groupName, group);
        }
        group.add(session.getChannel());
    }

    /**
     * 關(guān)閉連接， 關(guān)閉前發(fā)送一條通知消息
     */
    public void closeSession(SocketSession session, String echo) {
        ChannelFuture sendFuture = session.getChannel().writeAndFlush(new TextWebSocketFrame(echo));
        sendFuture.addListener(new ChannelFutureListener() {
            public void operationComplete(ChannelFuture future) {
                System.out.println("關(guān)閉連接："+echo);
                future.channel().close();
            }
        });
    }

    /**
     * 關(guān)閉連接
     */
    public void closeSession(SocketSession session) {

        ChannelFuture sendFuture = session.getChannel().close();
        sendFuture.addListener(new ChannelFutureListener() {
            public void operationComplete(ChannelFuture future) {
                System.out.println("發(fā)送所有完成："+session.getUser().getNickname());
            }
        });

    }

    /**
     * 發(fā)送消息
     * @param ctx 上下文
     * @param msg 待發(fā)送的消息
     */
    public void sendMsg(ChannelHandlerContext ctx, String msg) {
        ChannelFuture sendFuture = ctx.writeAndFlush(new TextWebSocketFrame(msg));
        sendFuture.addListener(f -> {//發(fā)送監(jiān)聽
            System.out.println("對(duì)所有發(fā)送完成："+msg);
        });
    }
}

package com.example.demo;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.AttributeKey;

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

public class SocketSession {

    public static final AttributeKey<SocketSession> SESSION_KEY = AttributeKey.valueOf("SESSION_KEY");

    /**
     * 用戶實(shí)現(xiàn)服務(wù)端會(huì)話管理的核心
     */
// 通道
    private Channel channel;
    // 用戶
    private User user;

    // session唯一標(biāo)示
    private final String sessionId;

    private String group;

    /**
     * session中存儲(chǔ)的session 變量屬性值
     */
    private Map<String, Object> map = new HashMap<String, Object>();

    public SocketSession(Channel channel) {//注意傳入?yún)?shù)channel。不同客戶端會(huì)有不同channel
        this.channel = channel;
        this.sessionId = buildNewSessionId();
        channel.attr(SocketSession.SESSION_KEY).set(this);
    }

    // 反向?qū)Ш?
    public static SocketSession getSession(ChannelHandlerContext ctx) {//注意ctx，不同的客戶端會(huì)有不同ctx
        Channel channel = ctx.channel();
        return channel.attr(SocketSession.SESSION_KEY).get();
    }

    // 反向?qū)Ш?
    public static SocketSession getSession(Channel channel) {
        return channel.attr(SocketSession.SESSION_KEY).get();
    }

    public String getId() {
        return sessionId;
    }

    private static String buildNewSessionId() {
        String uuid = UUID.randomUUID().toString();
        return uuid.replaceAll("-", "");
    }

    public synchronized void set(String key, Object value) {
        map.put(key, value);
    }

    public synchronized <T> T get(String key) {
        return (T) map.get(key);
    }

    public boolean isValid() {
        return getUser() != null ? true : false;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public String getGroup() {
        return group;
    }

    public void setGroup(String group) {
        this.group = group;
    }

    public Channel getChannel() {
        return channel;
    }
}

package com.example.demo;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.codec.http.websocketx.extensions.compression.WebSocketServerCompressionHandler;
import io.netty.handler.stream.ChunkedWriteHandler;
import io.netty.handler.timeout.IdleStateHandler;

import java.util.concurrent.TimeUnit;

public class WebSocketServer {

    private static WebSocketServer wbss;

    private static final int READ_IDLE_TIME_OUT = 60; // 讀超時(shí)
    private static final int WRITE_IDLE_TIME_OUT = 0;// 寫超時(shí)
    private static final int ALL_IDLE_TIME_OUT = 0; // 所有超時(shí)

    public static WebSocketServer inst() {
        return wbss = new WebSocketServer();
    }

    public void run(int port) {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        ServerBootstrap b = new ServerBootstrap();
        b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer <SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ChannelPipeline pipeline = ch.pipeline();
                        // Netty自己的http解碼器和編碼器，報(bào)文級(jí)別 HTTP請(qǐng)求的解碼和編碼
                        pipeline.addLast(new HttpServerCodec());
                        // ChunkedWriteHandler 是用于大數(shù)據(jù)的分區(qū)傳輸
                        // 主要用于處理大數(shù)據(jù)流，比如一個(gè)1G大小的文件如果你直接傳輸肯定會(huì)撐暴jvm內(nèi)存的;
                        // 增加之后就不用考慮這個(gè)問題了
                        pipeline.addLast(new ChunkedWriteHandler());
                        // HttpObjectAggregator 是完全的解析Http消息體請(qǐng)求用的
                        // 把多個(gè)消息轉(zhuǎn)換為一個(gè)單一的完全FullHttpRequest或是FullHttpResponse，
                        // 原因是HTTP解碼器會(huì)在每個(gè)HTTP消息中生成多個(gè)消息對(duì)象HttpRequest/HttpResponse,HttpContent,LastHttpContent
                        pipeline.addLast(new HttpObjectAggregator(64 * 1024));
                        // WebSocket數(shù)據(jù)壓縮
                        pipeline.addLast(new WebSocketServerCompressionHandler());
                        // WebSocketServerProtocolHandler是配置websocket的監(jiān)聽地址/協(xié)議包長(zhǎng)度限制
                        pipeline.addLast(new WebSocketServerProtocolHandler("/ws", null, true, 10 * 1024));

                        // 當(dāng)連接在60秒內(nèi)沒有接收到消息時(shí)，就會(huì)觸發(fā)一個(gè) IdleStateEvent 事件，
                        // 此事件被 HeartbeatHandler 的 userEventTriggered 方法處理到
                        pipeline.addLast(
                                new IdleStateHandler(READ_IDLE_TIME_OUT, WRITE_IDLE_TIME_OUT, ALL_IDLE_TIME_OUT, TimeUnit.SECONDS));

                        // WebSocketServerHandler、TextWebSocketFrameHandler 是自定義邏輯處理器，
                        pipeline.addLast(new WebSocketTextHandler());
                    }
                });
        Channel ch = b.bind(port).syncUninterruptibly().channel();
        ch.closeFuture().syncUninterruptibly();

        // 返回與當(dāng)前Java應(yīng)用程序關(guān)聯(lián)的運(yùn)行時(shí)對(duì)象
        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                SessionGroup.inst().shutdownGracefully();
                bossGroup.shutdownGracefully();
                workerGroup.shutdownGracefully();
            }
        });
    }
}

package com.example.demo;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;

import java.util.HashMap;
import java.util.Map;


public class WebSocketTextHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {

    //@Override
    protected void channelRead(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
        SocketSession session = SocketSession.getSession(ctx);
        TypeToken<HashMap<String, String>> typeToken = new TypeToken<HashMap<String, String>>() {
        };

        Gson gson=new Gson();
        java.util.Map<String,String> map = gson.fromJson(msg.text(), typeToken.getType());
        User user = null;
        switch (map.get("type")) {
            case "msg":
                Map<String, String> result = new HashMap<>();
                user = session.getUser();
                result.put("type", "msg");
                result.put("msg", map.get("msg"));
                result.put("sendUser", user.getNickname());
                SessionGroup.inst().sendToOthers(result, session);
                break;
            case "init":
                String room = map.get("room");
                session.setGroup(room);
                String nick = map.get("nick");
                user = new User(session.getId(), nick);
                session.setUser(user);
                SessionGroup.inst().addSession(session);
                break;
        }
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {

        // 是否握手成功，升級(jí)為 Websocket 協(xié)議
        if (evt == WebSocketServerProtocolHandler.ServerHandshakeStateEvent.HANDSHAKE_COMPLETE) {
            // 握手成功，移除 HttpRequestHandler，因此將不會(huì)接收到任何消息
            // 并把握手成功的 Channel 加入到 ChannelGroup 中
            new SocketSession(ctx.channel());
        } else if (evt instanceof IdleStateEvent) {
            IdleStateEvent stateEvent = (IdleStateEvent) evt;
            if (stateEvent.state() == IdleState.READER_IDLE) {
                System.out.println("bb22");
            }
        } else {
            super.userEventTriggered(ctx, evt);
        }
    }


    @Override
    protected void messageReceived(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {

    }
}

<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>群聊天室</title>     
    <style type="text/css">
    body {
        margin-right:50px;
        margin-left:50px;
    }
    .ddois {
        position: fixed;
        left: 120px;
        bottom: 30px;       
    }
    </style>        
</head>
<body>
     群名：<input type="text" id="room" name="group" placeholder="請(qǐng)輸入群">
    <br /><br />
     昵稱：<input type="text" id="nick" name="name" placeholder="請(qǐng)輸入昵稱">
    <br /><br />
    <button type="button" onclick="enter()">進(jìn)入聊天群</button>
    <br /><br />        
    <div id="message"></div>
    <br /><br />        
    <div class="ddois">
    <textarea name="send" id="text" rows="10" cols="30" placeholder="輸入發(fā)送消息"></textarea>
    <br /><br />
    <button type="button" onclick="send()">發(fā)送</button>
    </div>      
    <script type="text/javascript">
        var webSocket;
        
        if (window.WebSocket) {
            webSocket = new WebSocket("ws://localhost:53134/ws");
        } else {
            alert("抱歉，您的瀏覽器不支持WebSocket協(xié)議!");
        }
        
        //連通之后的回調(diào)事件
        webSocket.onopen = function() {
            console.log("已經(jīng)連通了websocket");
//                setMessageInnerHTML("已經(jīng)連通了websocket");
        };
        //連接發(fā)生錯(cuò)誤的回調(diào)方法
        webSocket.onerror = function(event){
            console.log("出錯(cuò)了");
//              setMessageInnerHTML("連接失敗");
        };
        
        //連接關(guān)閉的回調(diào)方法
        webSocket.onclose = function(){
            console.log("連接已關(guān)閉...");

        }
        
            //接收到消息的回調(diào)方法
        webSocket.onmessage = function(event){
            console.log("bbdds");
            var data = JSON.parse(event.data)
            var msg = data.msg;
            var nick = data.sendUser;
            switch(data.type){
                case 'init':
                    console.log("mmll");
                    break;
                case 'msg':
                    console.log("bblld");
                    setMessageInnerHTML(nick+":  "+msg);
                    break;
                default:
                    break;
            }
        }           
        function enter(){
            var map = new Map();
            var nick=document.getElementById('nick').value;
            var room=document.getElementById('room').value;
            map.set("type","init");
            map.set("nick",nick);
            console.log(room);
            map.set("room",room);
            var message = Map2Json(map);
            webSocket.send(message);                    
        }
        
        function send() {
            var msg = document.getElementById('text').value;
            var nick = document.getElementById('nick').value;
            console.log("1:"+msg);
            if (msg != null && msg != ""){
                var map = new Map();
                map.set("type","msg");
                map.set("msg",msg);
                var map2json=Map2Json(map);
                if (map2json.length < 8000){
                    console.log("4:"+map2json);
                    webSocket.send(map2json);
                }else {
                    console.log("文本太長(zhǎng)了，少寫一點(diǎn)吧??");
                }
            }
        }
        
        //將消息顯示在網(wǎng)頁(yè)上
        function setMessageInnerHTML(innerHTML) {
            document.getElementById("message").innerHTML += innerHTML + "<br/>";
        }
   
        function Map2Json(map) {
            var str = "{";
            map.forEach(function (value, key) {
                str += '"'+key+'"'+':'+ '"'+value+'",';
            })
            str = str.substring(0,str.length-1)
            str +="}";
            return str;
        }        
    
    </script>

</body> 
</html>