springboot和netty整合的聊天室--群聊

springboot和netty都是热门的框架，整合在一起，实现一个简单聊天室。这个聊天室只有群聊功能。基于websocket协议实现的。
废话不多说，看代码
springboot的pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.2.RELEASE</version>
    <relativePath />
    <!-- lookup parent from repository -->
</parent>
<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>  
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-all</artifactId>
        <version>4.1.41.Final</version>
    </dependency>
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.8.5</version>
    </dependency>
</dependencies>

在入口类处添加代码如下

public static void main(String[] args) throws UnknownHostException {
    ConfigurableApplicationContext application = SpringApplication.run(Appyingyong.class, args);
    Environment env = application.getEnvironment();
    String host = InetAddress.getLocalHost().getHostAddress();
    String port = env.getProperty("server.port");
    System.out.println("[----------------------------------------------------------]");
    System.out.println("聊天室启动成功！点击进入:\t http://" + host + ":" + port);
    System.out.println("[----------------------------------------------------------");          
    WebSocketServer.inst().run(9999);
}

netty服务端代码

public class WebSocketServer {

private static WebSocketServer wbss;

private static final int READ_IDLE_TIME_OUT = 60; // 读超时 s
private static final int WRITE_IDLE_TIME_OUT = 0;// 写超时
private static final int ALL_IDLE_TIME_OUT = 0; // 所有超时

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解码器和编码器，报文级别 HTTP请求的解码和编码
                    pipeline.addLast(new HttpServerCodec());
                    // ChunkedWriteHandler 是用于大数据的分区传输
                    // 主要用于处理大数据流，比如一个1G大小的文件如果你直接传输肯定会撑暴jvm内存的;
                    // 增加之后就不用考虑这个问题了
                    pipeline.addLast(new ChunkedWriteHandler());
                    // HttpObjectAggregator 是完全的解析Http消息体请求用的
                    // 把多个消息转换为一个单一的完全FullHttpRequest或是FullHttpResponse，
                    // 原因是HTTP解码器会在每个HTTP消息中生成多个消息对象HttpRequest/HttpResponse,HttpContent,LastHttpContent
                    pipeline.addLast(new HttpObjectAggregator(64 * 1024));
                    // WebSocket数据压缩
                    pipeline.addLast(new WebSocketServerCompressionHandler());
                    // WebSocketServerProtocolHandler是配置websocket的监听地址/协议包长度限制
                    pipeline.addLast(new WebSocketServerProtocolHandler("/ws", null, true, 10 * 1024));

                    // 当连接在60秒内没有接收到消息时，就会触发一个 IdleStateEvent 事件，
                    // 此事件被 HeartbeatHandler 的 userEventTriggered 方法处理到
                    pipeline.addLast(
                            new IdleStateHandler(READ_IDLE_TIME_OUT, WRITE_IDLE_TIME_OUT, ALL_IDLE_TIME_OUT, TimeUnit.SECONDS));

                    // WebSocketServerHandler、TextWebSocketFrameHandler 是自定义逻辑处理器，
                    pipeline.addLast(new WebSocketTextHandler());
                }
            });
    Channel ch = b.bind(port).syncUninterruptibly().channel();
    ch.closeFuture().syncUninterruptibly();
    
    // 返回与当前Java应用程序关联的运行时对象
    Runtime.getRuntime().addShutdownHook(new Thread() {
        @Override
        public void run() {
            SessionGroup.inst().shutdownGracefully();
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    });
}   
}

自定义的Handler

public class WebSocketTextHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {

@Override
protected void channelRead0(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();
    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，升级为 Websocket 协议
    if (evt == WebSocketServerProtocolHandler.ServerHandshakeStateEvent.HANDSHAKE_COMPLETE) {
        // 握手成功，移除 HttpRequestHandler，因此将不会接收到任何消息
        // 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);
    }       
}   
}

SessionGroup类代码

public final class SessionGroup {

private static SessionGroup singleInstance = new SessionGroup();    

// 组的映射
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) {
    // 获取组
    ChannelGroup group = groupMap.get(s.getGroup());
    if (null == group) {
        return;
    }
    Gson gson=new Gson();       
    String json = gson.toJson(result);
    // 自己发送的消息不返回给自己
//      Channel channel = s.getChannel();
    // 从组中移除通道
//      group.remove(channel);
    ChannelGroupFuture future = group.writeAndFlush(new TextWebSocketFrame(json));
    future.addListener(f -> {
        System.out.println("完成发送："+json);
//          group.add(channel);//发送消息完毕重新添加。

    });
}

public void addSession(SocketSession session) {

    String groupName = session.getGroup();
    if (StringUtils.isEmpty(groupName)) {
        // 组为空，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());
}

/**
 * 关闭连接， 关闭前发送一条通知消息
 */
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("关闭连接："+echo);
            future.channel().close();
        }
    });
}

/**
 * 关闭连接
 */
public void closeSession(SocketSession session) {

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

}

/**
 * 发送消息
 * @param ctx 上下文
 * @param msg 待发送的消息
 */
public void sendMsg(ChannelHandlerContext ctx, String msg) {
    ChannelFuture sendFuture = ctx.writeAndFlush(new TextWebSocketFrame(msg));
    sendFuture.addListener(f -> {//发送监听
        System.out.println("对所有发送完成："+msg);
    });
}   
}

SocketSession类如下

public class SocketSession {

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

/**
 * 用户实现服务端会话管理的核心
 */
// 通道
private Channel channel;
// 用户
private User user;

// session唯一标示
private final String sessionId;

private String group;

/**
 * session中存储的session 变量属性值
 */
private Map<String, Object> map = new HashMap<String, Object>();

public SocketSession(Channel channel) {//注意传入参数channel。不同客户端会有不同channel
    this.channel = channel;
    this.sessionId = buildNewSessionId();
    channel.attr(SocketSession.SESSION_KEY).set(this);
}

// 反向导航
public static SocketSession getSession(ChannelHandlerContext ctx) {//注意ctx，不同的客户端会有不同ctx
    Channel channel = ctx.channel();
    return channel.attr(SocketSession.SESSION_KEY).get();
}

// 反向导航
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;
}   
}

User类

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;
}
}

服务端的代码已完成，下面进行测试。写了一个简单html文件进行测试

<!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="请输入群">
    <br /><br />
     昵称：<input type="text" id="nick" name="name" placeholder="请输入昵称">
    <br /><br />
    <button type="button" onclick="enter()">进入聊天群</button>
    <br /><br />        
    <div id="message"></div>
    <br /><br />        
    <div class="ddois">
    <textarea name="send" id="text" rows="10" cols="30" placeholder="输入发送消息"></textarea>
    <br /><br />
    <button type="button" onclick="send()">发送</button>
    </div>      
    <script type="text/javascript">
        var webSocket;
        
        if (window.WebSocket) {
            webSocket = new WebSocket("ws://localhost:9999/ws");
        } else {
            alert("抱歉，您的浏览器不支持WebSocket协议!");
        }
        
        //连通之后的回调事件
        webSocket.onopen = function() {
            console.log("已经连通了websocket");
//                setMessageInnerHTML("已经连通了websocket");
        };
        //连接发生错误的回调方法
        webSocket.onerror = function(event){
            console.log("出错了");
//              setMessageInnerHTML("连接失败");
        };
        
        //连接关闭的回调方法
        webSocket.onclose = function(){
            console.log("连接已关闭...");

        }
        
            //接收到消息的回调方法
        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("文本太长了，少写一点吧😭");
                }
            }
        }
        
        //将消息显示在网页上
        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>

在浏览器随便打开两个网页，然后都输入http://localhost:8111/
测试效果如下图

cheng1.jpg

cheng2.jpg

输入相同群名，就可以进入群聊。如果群名不同，会看不到在别的群留言