背景

客服类型的网页聊天工具，客户点击以后，自动分配一个已在线的客服给对接回答问题。

用netty当作服务端。用简单的html语言搭建网页，消息记录存储在sessionStorage中，勉强实现了消息记录的功能

效果如图

后续：目前实现的功能，应该是可以满足小范围的使用。毕竟每个客户都会建立一条ws链接。没测试过具体能够抗住多少并发

服务端

构建服务器的server

public class NettyWebSocketServer implements Runnable {

    // 创建两个线程组 boosGroup、workerGroup
    EventLoopGroup bossGroup = new NioEventLoopGroup(1);
    EventLoopGroup workerGroup = new NioEventLoopGroup();

    @PreDestroy
    public void close() {
        bossGroup.shutdownGracefully();
        workerGroup.shutdownGracefully();
    }

    @Override
    public void run() {
        try {
            // 创建服务端的启动对象，设置参数
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup)
                // 设置服务端通道实现类型
                .channel(NioServerSocketChannel.class)
                // 设置线程队列得到连接个数
                .option(ChannelOption.SO_BACKLOG, 128)
                // 设置保持活动连接状态
                .childOption(ChannelOption.SO_KEEPALIVE, true).childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel channel) throws Exception {
                        // 给pipeline管道设置处理器
                        channel.pipeline()
                            // 对http的支持
                            .addLast(new HttpServerCodec())
                            // 对大数据块的支持
                            .addLast(new ChunkedWriteHandler())
                            // post请求分三部分. request line / request header / message body
                            // HttpObjectAggregator将多个信息转化成单一的request或者response对象
                            .addLast(new HttpObjectAggregator(8000))
                            // 将http协议升级为ws协议. websocket的支持
                            .addLast(new WebSocketServerProtocolHandler("/chat")).addLast(new WebSocketHandler());
                    }
                });
            // 绑定端口号，启动服务端
            ChannelFuture channelFuture = bootstrap.bind(8888).sync();
            System.out.println("java技术爱好者的服务端已经准备就绪...");
            // 对关闭通道进行监听
            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

消息处理：这边设定的是客服都以“客服”命名开头, 一个客服可以和多个人聊天。其他客户访问网页时就会和某个客户建立1对1聊天

其次是消息处理格式需要是TextWebSocketFrame。这个是封装后的和网页ws交互的消息格式。

public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
    public static Map<String, Channel> users = new HashMap<>();

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        super.channelActive(ctx);
        System.out.println("有新链接");
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        super.channelInactive(ctx);
        System.out.println("端口链接");
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame textWebSocketFrame) throws Exception {
        String msgStr = textWebSocketFrame.text();
        System.out.println("msg:" + msgStr);
         获取客户端发送过来的消息
        Message msg = JSON.parseObject(msgStr, Message.class);
        System.out.println("接收到消息：" + JSON.toJSONString(msg));
        switch (msg.getType()) {
            case "register":
                users.put(msg.getSrcUserId(), ctx.channel());
                if (!msg.getSrcUserId().startsWith("客服")) {
                    String onlineWorker = getOnlineWorker();
                    if (onlineWorker == null) {
                        break;
                    }
                    Message res = new Message();
                    res.setType("init_user");
                    res.setSrcUserName(onlineWorker);
                    res.setSrcUserId(onlineWorker);
                    res.setContent(String.format("你好,%s很高兴为你服务", onlineWorker));
                    ctx.channel().writeAndFlush(new TextWebSocketFrame(JSON.toJSONString(res)));

                    res.setSrcUserId(msg.getSrcUserId());
                    res.setSrcUserName(msg.getSrcUserName());
                    res.setContent("...");
                    users.get(onlineWorker).writeAndFlush(new TextWebSocketFrame(JSON.toJSONString(res)));
                }
                break;
            case "group":
                for (Entry<String, Channel> entry : users.entrySet()) {
                    if (entry.getKey().equals(msg.getSrcUserId())) {
                        continue;
                    }
                    entry.getValue().writeAndFlush(textWebSocketFrame);
                }
                break;
            default:
                Channel dstChannel = users.get(msg.getDestUserId());
                if (dstChannel == null) {
                    msg.setContent("sorry, I'am not online, please contact me later");
                    msg.setSrcUserName(msg.getDestUserName());
                    msg.setSrcIconUrl(msg.getDestIconUrl());
                    ctx.channel().writeAndFlush(new TextWebSocketFrame(JSON.toJSONString(msg)));
                } else {
                    dstChannel.writeAndFlush(new TextWebSocketFrame(msgStr));
                }

        }
    }

    private String getOnlineWorker() {
        Map<String, Channel> users = WebSocketHandler.users;
        for (String user : users.keySet()) {
            if (user != null && user.startsWith("客服")) {
                return user;
            }
        }
        return null;
    }
}

服务端的逻辑不算多。主要是构建一个消息交换的通道。

网页端

网页是基于一个网上的聊天模板改的。html内容如下：

左侧：根据聊天信息渲染左侧人名
左侧：根据聊天内容，显示最后一条内容
右侧：根据当前选中的人名，渲染聊天内容
右侧：他人聊天内容在左边，自己的在右边
html的访问链接在query位置带上参数user=你的昵称

各类图片头像什么的随便网上抄一抄完事

<!doctype html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>PC聊天</title>
    <link rel="stylesheet" href="../static/css/session-eg.css">
</head>

<body>
    <div class="main">
        <div class="top">
            <div class="top-left">
                <div class="header"></div>
                <div class="search">
                    <input type="text">
                    <i class="icon-sear"></i>
                </div>
            </div>
            <div class="top-type">
                <a href="#" class="news icon-site"></a>
                <a href="#" class="friend icon-site"></a>
                <a href="#" class="file icon-site"></a>
            </div>
            <div class="top-right">
                <i class="ic-menu ic-same"></i>
                <i class="ic-shrink ic-same"></i>
                <i class="ic-boost ic-same"></i>
                <i class="ic-close ic-same"></i>
            </div>
        </div>
        <div class="box">
            <div class="chat-list" id="chat-list">
            </div>
            <div class="box-right">
                <div class="recvfrom">
                    <div class="nav-top">
                        <p id="self-chat_userName">公众号</p>
                    </div>
                    <div class="news-top">
                        <ul id="self-chat">

                        </ul>
                    </div>
                </div>
                <div class="sendto">
                    <div class="but-nav">
                        <ul>
                            <li class="font"></li>
                            <li class="face"></li>
                            <li class="cut"></li>
                            <li class="page"></li>
                            <li class="old"></li>
                        </ul>
                    </div>
                    <div class="but-text">
                        <textarea name="" id="chatMessage" cols="110" rows="6"></textarea>
                        <button class="button" onclick="sendMessage()" type="submit">发送</button>
                        <!-- <a href="#" class="button" onchange="sendMessage()">发送</a> -->
                    </div>
                </div>
            </div>

        </div>


    </div>

</body>
<script>
    function showChatUserName(name) {
        document.getElementById('self-chat_userName').innerHTML = name
    }
    function buildLeft(user) {
        old = document.getElementById(user.id)
        if (old != null) {
            return;
        }
        usersBox = document.getElementById("chat-list")
        userDiv = document.createElement('div')
        userDiv.innerHTML = `<div class="list-box" onclick="chooseOne(this)" id="${user.id}">
                    <img class="chat-head" src="../static/img/img-header2.jpg" alt="">
                    <div class="chat-rig">
                        <p class="title" id='name'>${user.name}</p>
                        <p class="text" id='${user.id}_last'>${user.lastMsg}</p>
                    </div>
                </div>`
        selectUser = document.getElementsByClassName('list-box select')
        if (selectUser.length == 0) {
            userDiv.className = 'list-box select'
            sessionStorage.setItem("dst", user.id)
            showChatUserName(user.name)
        }
        usersBox.appendChild(userDiv)
    }
    function buildNews(type, msg) {
        msgLi = document.createElement('li')
        msgLi.innerHTML = `<li class="${type}">
                                <div class="avatar"><img src="../static/img/img-header2.jpg" alt=""></div>
                                <div class="msg">
                                    <p class="msg-name">${msg.userName}</p>
                                    <p class="msg-text">${msg.message}</p><time>${msg.time}</time>
                                </div>
                            </li>`
        document.getElementById('self-chat').appendChild(msgLi)
    }

    function getUserName() {
        var url = new URL(window.location.href)
        return url.searchParams.get('user')
    }

    function getDst() {
        result = sessionStorage.getItem("dst");
        src = getUserName()
        if (src == result) {
            return 'unknown'
        } else {
            return result
        }
    }

    function record(userId, record) {
        msgsJSON = sessionStorage.getItem(userId)
        msgsObj = JSON.parse(msgsJSON)
        if (msgsObj == 'undefined' || msgsObj == null) {
            msgsObj = []
        }
        console.log(msgsObj)
        msgsObj.push(record)
        sessionStorage.setItem(userId, JSON.stringify(msgsObj))
    }
    function empty(e) {
        while (e.firstChild) {
            e.removeChild(e.firstChild);
        }
    }
    function showHistory(userId) {
        newsDiv = document.getElementById('self-chat')
        empty(newsDiv)
        msgsJSON = sessionStorage.getItem(userId)
        msgsObj = JSON.parse(msgsJSON)
        curUsr = getUserName()
        for (i in msgsObj) {
            var record = msgsObj[i]
            buildNews(record.type, record.value)
        }
    }
    var ws = new WebSocket("ws://localhost:8888/chat");
    ws.onopen = function () {
        console.log("连接成功.")
        var serverMsg = {
            "type": "register",
            "srcUserId": getUserName(),
            "srcUserName": getUserName()
        }
        ws.send(JSON.stringify(serverMsg))
    }
    ws.onmessage = function (evt) {
        console.log(evt)
        data = JSON.parse(evt.data)
        if (data.type == 'init_user') {
            buildLeft({ 'name': data.srcUserName, 'lastMsg': data.content, 'id': data.srcUserId })
            showMessage(data)
        } else {
            showMessage(data);
        }
    }
    function showMessage(data) {
        var msg = {
            "userName": data.srcUserName,
            "message": data.content,
            "iconUrl": "../static/img/img-header2.jpg",
            "time": "20:19"
        }
        if (getDst() == data.srcUserId) {

            buildNews('other', msg)
        }

        showLast(data.srcUserId, data.content)
        record(data.srcUserId, { "type": 'other', "value": msg })
    }
    function recordLeft(userId, last) {
        leftMap = JSON.parse(sessionStorage.getItem('chat-left'))
        if (leftMap == null || leftMap == 'undefined') {
            leftMap = new Map()
        }
        leftMap[userId] = last
        sessionStorage.setItem('chat-left', JSON.stringify(leftMap))
    }
    function showLeft() {
        leftMap = JSON.parse(sessionStorage.getItem('chat-left'))

        if (leftMap == null || leftMap == 'undefined') {
            return;
        }
        keys = Object.keys(leftMap)
        for (i in keys) {
            buildLeft({ 'name': keys[i], 'lastMsg': leftMap[keys[i]], 'id': keys[i] })
        }

    }
    function showLast(userId, content) {
        lastP = document.getElementById(userId + "_last")
        lastP.innerHTML = content
        recordLeft(userId, content)
    }
    function sendMessage() {
        msg = {
            "userName": getUserName(),
            "message": document.getElementById('chatMessage').value,
            "iconUrl": "../static/img/img-header2.jpg",
            "time": "20:21"
        }
        buildNews('self', msg)
        messageObj = {
            "srcUserName": getUserName(),
            "srcUserId": getUserName(),
            "srcIconUrl": msg.iconUrl,
            "type": "self-chat",
            "content": msg.message,
            "time": msg.time,
            "destUserId": getDst(),
            "destUserName": getDst(),
            "destIconUrl": msg.iconUrl
        }
        ws.send(JSON.stringify(messageObj))
        record(messageObj.destUserId, { "type": "self", "value": msg })
        document.getElementById('chatMessage').val('')
    }
    function chooseOne(ele) {
        old = document.getElementsByClassName('list-box select')
        for (i in old) {
            old[i].className = 'list-box'
        }
        ele.className = 'list-box select'
        var user = {
            "id": ele.id,
            "name": ele.children[1].children[0].innerHTML
        }
        console.log(user)
        sessionStorage.setItem("dst", user.id)
        showChatUserName(user.name)
        showHistory(user.id)
    }
    function init() {
        showLeft()
        dst = sessionStorage.getItem('dst')
        if (dst != null && dst != 'undefined') {
            showHistory(dst)
            showChatUserName(dst)
        }
    }
    init()
</script>

</html>

css内容如下：

* {
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: 14px;
    text-decoration: none;
    color: black;
    outline: none;
}
 
html, body {
    width: 100%;
    height: 100%;
}
 
.main {
 
    height: 800px;
    width: 1005px;
    margin: auto;
    box-shadow: 0 0 3px 5px #e1e1e1;
}
 
.main .top {
    width: 1005px;
    height: 60px;
    background-color: #3bb4f2;
    border-top-left-radius: 10px;
    border-top-right-radius: 10px;
}
 
.main .top .top-left {
    height: 100%;
    width: 200px;
    float: left;
    position: relative;
}
 
.main .top .top-left .header {
    height: 48px;
    width: 48px;
    border-radius: 50%;
    background-image: url("../img/header.jpg");
    line-height: 60px;
    display: inline-block;
    margin: 6px;
    border: 1px solid transparent;
}
 
.main .top .top-left .header:hover {
    border: 1px solid white;
}
 
.main .top .top-left .search {
    display: inline-block;
    height: 30px;
    position: absolute;
    margin: 17px 14px;
}
 
.main .top .top-left .search input {
    display: inline-block;
    width: 110px;
    height: 30px;
    border-radius: 40px;
    border: 1px solid ghostwhite;
    text-indent: 40px;
    background-color: #3bb4f2;
 
}
 
.main .top .top-left .search input:hover {
    border: 1px solid white;
}
 
.main .top .top-left .search .icon-sear {
 
    background-image: url("../img/sou.png");
    background-size: 100% 100%;
    height: 30px;
    width: 30px;
    position: absolute;
    margin-top: -31px;
    margin-left: 7px;
 
}
 
.main .top .top-type {
    height: 100%;
    width: 200px;
    float: left;
    margin-left: 200px;
}
 
.main .top .top-type a.icon-site {
    display: inline-block;
    height: 40px;
    width: 40px;
    background-size: 100% 100%;
    margin: 10px 11px;
}
 
.main .top .top-type .news {
    background-image: url("../img/news.png");
 
}
 
.main .top .top-type .friend {
    background-image: url("../img/friend.png");
 
}
 
.main .top .top-type .file {
    background-image: url("../img/file.png");
 
}
 
.main .top .top-right {
    height: 100%;
    width: 200px;
    float: right;
}
 
.main .top .top-right i.ic-same {
    display: inline-block;
    height: 20px;
    width: 20px;
    background-size: 100% 100%;
    margin: 19px 7px;
}
 
.main .top .top-right i.ic-same.ic-menu {
    margin-left: 48px;
}
 
.main .top .top-right .ic-menu {
 
    background-image: url("../img/menu.png");
}
 
.main .top .top-right .ic-menu:hover {
    background-image: url("../img/menu (1).png");
}
 
.main .top .top-right .ic-shrink {
    background-image: url("../img/shrink.png");
}
 
.main .top .top-right .ic-shrink:hover {
    background-image: url("../img/shrink (1).png");
}
 
.main .top .top-right .ic-boost {
    background-image: url("../img/boost.png");
}
 
.main .top .top-right .ic-boost:hover {
    background-image: url("../img/boost (1).png")
}
 
.main .top .top-right .ic-close {
    background-image: url("../img/close.png");
}
 
.main .top .top-right .ic-close:hover {
    background-image: url("../img/close (1).png");
}
 
.main .box {
    width: 100%;
    height: 740px;
 
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
}
 
.main .box .chat-list {
    float: left;
    width: 250px;
    height: 100%;
    background-color: #f4f4f4;
}
 
.main .box .chat-list .list-box {
    height: 80px;
    width: 250px;
}
 
.main .box .chat-list .list-box.select {
    background-color: #dbdbdb;
}
 
.main .box .chat-list .list-box:hover {
    background-color: #dbdbdb;
}
 
.main .box .chat-list .list-box img.chat-head {
    height: 50px;
    width: 50px;
    border-radius: 50%;
    border: 1px solid #f4f4f4;
    margin: 15px 10px;
}
 
.main .box .chat-list .list-box .chat-rig {
    float: right;
    height: 50px;
    width: 178px;
    margin: 15px 0;
}
 
.main .box .chat-list .list-box .chat-rig .title {
    font-weight: 600;
    font-size: 17px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
}
 
.main .box .chat-list .list-box .chat-rig .text {
    font-size: 12px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    color: #6C6C6C;
}
 
.main .box .box-right {
    float: left;
    width: 750px;
    height: 100%;
}
 
.main .box .box-right .recvfrom {
    width: 752px;
    height: 560px;
 
}
 
.main .box .box-right .recvfrom .nav-top {
    height: 45px;
    width: 100%;
}
 
.main .box .box-right .recvfrom .nav-top p {
    line-height: 45px;
    font-size: 18px;
    font-weight: 600;
    margin-left: 25px;
}
 
.main .box .box-right .recvfrom .news-top {
    height: 510px;
    border-top: 1px solid #6C6C6C;
    border-bottom: 1px solid #6C6C6C;
    overflow-y: scroll;
}
 
.main .box .box-right .recvfrom .news-top ul {
    height: 100%;
    width: 100%;
}
 
.main .box .box-right .recvfrom .news-top ul li {
    margin: 10px;
    min-height: 80px;
    position: relative;
    overflow: hidden;
 
}
 
.main .box .box-right .recvfrom .news-top ul li .avatar img {
    height: 30px;
    width: 30px;
    border-radius: 50%;
}
 
.main .box .box-right .recvfrom .news-top ul li .msg {
    top: -10px;
    margin: 8px;
    min-height: 80px;
}
 
.main .box .box-right .recvfrom .news-top ul li::after {
    clear: both;
    content: "";
    display: inline-block;
}
 
.main .box .box-right .recvfrom .news-top ul li .msg .msg-text {
    background-color: #6C6C6C;
    border-radius: 5px;
    padding: 8px;
}
 
.main .box .box-right .recvfrom .news-top ul li .msg time {
    float: right;
    color: #ccc;
}
 
.main .box .box-right .recvfrom .news-top ul li.other .avatar {
    position: absolute;
    left: 0;
    top: 0;
}
 
.main .box .box-right .recvfrom .news-top ul li.other .msg {
    position: absolute;
    left: 40px;
 
}
 
.main .box .box-right .recvfrom .news-top ul li.self .avatar {
    position: absolute;
    right: 0;
    top: 0;
}
 
.main .box .box-right .recvfrom .news-top ul li.self .msg {
    position: absolute;
    right: 38px;
}
 
.main .box .box-right .sendto {
    width: 752px;
    height: 180px;
}
 
.main .box .box-right .sendto .but-nav {
    height: 40px;
}
 
.main .box .box-right .sendto .but-nav ul li {
    float: left;
    height: 22px;
    width: 22px;
    margin: 7px 15px;
    background-size: 100% 100%;
}
 
.main .box .box-right .sendto .but-nav ul li:hover {
    background-color: #dbdbdb;
}
 
.main .box .box-right .sendto .but-nav ul li.font {
    background-image: url("../img/font.png");
}
 
.main .box .box-right .sendto .but-nav ul li.face {
    background-image: url("../img/face.png");
}
 
.main .box .box-right .sendto .but-nav ul li.cut {
    background-image: url("../img/cut.png");
}
 
.main .box .box-right .sendto .but-nav ul li.page {
    background-image: url("../img/page.png");
}
 
.main .box .box-right .sendto .but-nav ul li.old {
    background-image: url("../img/old.png");
}
 
.main .box .box-right .sendto .but-text textarea {
    border: none;
    font-size: 22px;
    margin-left: 20px;
    width: 732px;
    height: 100px;
}
 
.main .box .box-right .sendto .but-text .button {
    float: right;
    padding: 5px 25px;
    background-color: #3bb4f2;
    margin-right: 20px;
}

原文链接： https://blog.csdn.net/whylackgoodname/article/details/128408225