Java+Html实现前后端客服聊天

核心组件

网络通信层

• Bootstrap
  负责客户端启动并用来链接远程Netty Server;
• ServerBootStrap
  负责服务端监听，用来监听指定端口：
• Channel
  相当于完成网络通信的载体。

事件调度层

• EventLoopGroup
  本质上是一个线程池，主要负责接收/O请求，并分配线程执行处理请
• EventLoop
  相当于线程池中的线程。

服务编排层

• ChannelPipeline
  负责将多个ChannelHandler链接在一起。
• ChannelHandler
  针对l/O的数据处理器数据接收后，通过指定的Handleri进行处理。
• ChannelHandlerContext
  用来保存ChannelHandler的上下文信息。

Spring实现客服聊天

1. 新建一个maven项目
2. 引入依赖

        <dependency><groupId>io.netty</groupId><artifactId>netty-all</artifactId><version>4.1.99.Final</version></dependency>

3. 启动IMServer的方法

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;public class ImServer {/*** 启动IM服务器的方法*/public static void start() {// 创建两个EventLoopGroup，bossGroup用于处理连接请求，workerGroup用于处理已连接的客户端的I/O操作EventLoopGroup boss = new NioEventLoopGroup();EventLoopGroup worker = new NioEventLoopGroup();try {// 创建ServerBootstrap实例，用于配置服务器ServerBootstrap bootstrap = new ServerBootstrap();// 设置EventLoopGroupbootstrap.group(boss, worker)// 设置通道类型为NioServerSocketChannel.channel(NioServerSocketChannel.class)// 设置子处理器，用于处理新连接的初始化.childHandler(new ChannelInitializer<SocketChannel>() {@Overrideprotected void initChannel(SocketChannel socketChannel) throws Exception {// 在这里可以添加各种ChannelHandler来处理消息}});// 绑定服务器到指定端口，并同步等待成功ChannelFuture future = bootstrap.bind(8001).sync();// 等待服务器socket关闭future.channel().closeFuture().sync();} catch (InterruptedException e) {e.printStackTrace();} finally {// 优雅地关闭EventLoopGroupboss.shutdownGracefully();worker.shutdownGracefully();}}
}

4. 启动

public class ImApplication {public static void main(String[] args) {ImServer.start();}}

启动成功

技术方案对比

技术	说明	优点	缺点	适用场景
WebSocket	双向持久连接，服务器和客户端可以随时发送消息	低延迟、实时性强、双向通信	需要浏览器支持，可能被防火墙拦截	客服聊天、游戏、协作编辑
轮询（Polling）	客户端定期请求服务器获取新消息	兼容性好，所有浏览器支持	占用带宽，高并发时服务器压力大	简单场景，低频率更新的聊天
长轮询（Long Polling）	客户端请求后，服务器等待新消息再返回	比普通轮询节省带宽	服务器压力仍然较大	稍微实时的聊天应用
SSE（Server-Sent Events）	服务器单向推送消息到客户端	轻量级、兼容 HTTP/2	仅支持服务器向客户端推送	客服系统中的通知功能

WebScoket建立连接

1. 设置消息处理器

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
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.stream.ChunkedWriteHandler;public class ImServer {/*** 启动IM服务器的方法*/public static void start() {// 创建两个EventLoopGroup，bossGroup用于处理连接请求，workerGroup用于处理已连接的客户端的I/O操作EventLoopGroup boss = new NioEventLoopGroup();EventLoopGroup worker = new NioEventLoopGroup();try {// 创建ServerBootstrap实例，用于配置服务器ServerBootstrap bootstrap = new ServerBootstrap();// 设置EventLoopGroupbootstrap.group(boss, worker)// 设置通道类型为NioServerSocketChannel.channel(NioServerSocketChannel.class)// 设置子处理器，用于处理新连接的初始化.childHandler(new ChannelInitializer<SocketChannel>() {@Overrideprotected void initChannel(SocketChannel socketChannel) throws Exception {ChannelPipeline pipeline = socketChannel.pipeline();//用于HTTP请求和响应的编解码pipeline.addLast(new HttpServerCodec())//支持分块写入大文件或流式数据.addLast(new ChunkedWriteHandler())//将多个HTTP消息片段合并成一个完整的HTTP消息，最大聚合大小为64KB。.addLast(new HttpObjectAggregator(1024*64))// 添加WebSocket协议处理器，用于处理WebSocket握手和协议升级.addLast(new WebSocketServerProtocolHandler("/"))// 添加自定义的WebSocket业务逻辑处理器，用于处理WebSocket消息的接收和发送。.addLast(new WebSocketHandler());}});// 绑定服务器到指定端口，并同步等待成功ChannelFuture future = bootstrap.bind(8001).sync();// 等待服务器socket关闭future.channel().closeFuture().sync();} catch (InterruptedException e) {e.printStackTrace();} finally {// 优雅地关闭EventLoopGroupboss.shutdownGracefully();worker.shutdownGracefully();}}
}

2. 消息处理的实现

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {/*** 处理接收到的 TextWebSocketFrame 消息* @param channelHandlerContext 表示当前通道的上下文，包含与通道相关的所有信息和操作方法。*                              可用于执行如写数据、关闭通道、触发事件等操作。* @param textWebSocketFrame    表示接收到的 WebSocket 文本帧消息。*                              包含客户端发送的具体数据内容，可以通过其方法（如 text()）获取消息内容并进行处理。* @throws Exception*/@Overrideprotected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {System.out.println(textWebSocketFrame.text());}
}

3. 前端页面

<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>简单聊天页面</title><style>body { font-family: Arial, sans-serif; text-align: center; margin: 20px; }#chatBox { width: 100%; height: 300px; border: 1px solid #ccc; overflow-y: auto; padding: 10px; text-align: left; }#messageInput { width: 80%; padding: 8px; margin-top: 10px; }#sendBtn { padding: 8px; cursor: pointer; }</style>
</head>
<body><h2>简单 WebSocket 聊天</h2>
<div id="chatBox"></div>
<input type="text" id="messageInput" placeholder="输入消息...">
<button id="sendBtn">发送</button><script>// 连接 WebSocket 服务器const socket = new WebSocket("ws://localhost:8001");// 监听 WebSocket 连接socket.onopen = function () {console.log("WebSocket 已连接");appendMessage("✅ 连接成功");};// 监听收到的消息socket.onmessage = function (event) {appendMessage("💬 服务器: " + event.data);};// 监听 WebSocket 关闭socket.onclose = function () {appendMessage("❌ 连接已关闭");};// 监听发送按钮点击document.getElementById("sendBtn").addEventListener("click", function () {sendMessage();});// 监听回车键发送消息document.getElementById("messageInput").addEventListener("keypress", function (event) {if (event.key === "Enter") {sendMessage();}});// 发送消息function sendMessage() {const input = document.getElementById("messageInput");const message = input.value.trim();if (message) {socket.send(message);appendMessage("📝 我: " + message);input.value = "";}}// 在聊天框中追加消息function appendMessage(text) {const chatBox = document.getElementById("chatBox");const messageElement = document.createElement("p");messageElement.textContent = text;chatBox.appendChild(messageElement);chatBox.scrollTop = chatBox.scrollHeight; // 滚动到底部}
</script></body>
</html>

4. 启动测试
   

用户上线

1. 定义一个实体，用来接收消息

import lombok.Data;@Data
public class Command {private Integer code;private String name;}

2. 定义一个枚举，用来区分消息类型

import lombok.AllArgsConstructor;
import lombok.Getter;@Getter
@AllArgsConstructor
public enum CommandType {/*** 登陆连接*/CONNECTION(1001),/*** 错误*/ERROR(-1);private final Integer code;public static CommandType getCommandType(Integer code) {for (CommandType commandType : CommandType.values()) {if (commandType.getCode().equals(code)) {return commandType;}}return ERROR;}
}

3. ImServer定义一个map，用来存储登陆的用户

public static final ConcurrentHashMap<String, Channel> USERS = new ConcurrentHashMap<>(1024);

4. 添加一个登陆处理的实现类ConnectionHandler

import com.wzw.Command;
import com.wzw.ImServer;
import com.wzw.Result;
import io.netty.channel.ChannelHandlerContext;public class ConnectionHandler {/*** 处理客户端的连接请求** @param channelHandlerContext 与客户端通信的ChannelHandlerContext* @param command 包含客户端发送的命令信息*/public static void execute(ChannelHandlerContext channelHandlerContext, Command command) {// 检查用户名是否已经存在if (ImServer.USERS.containsKey(command.getName())) {// 如果用户名重复，发送失败消息channelHandlerContext.channel().writeAndFlush(Result.fail("用户名重复"));//并断开连接channelHandlerContext.disconnect();return;}// 将新的用户添加到在线用户列表中ImServer.USERS.put(command.getName(), channelHandlerContext.channel());// 发送连接成功的消息channelHandlerContext.channel().writeAndFlush(Result.success("连接成功"));// 发送当前在线用户列表channelHandlerContext.channel().writeAndFlush(Result.success("当前在线用户：" + ImServer.USERS.keySet()));}
}

5. WebSocketHandler中添加消息处理的实现，如果登陆服务，调用ConnectionHandler

import com.alibaba.fastjson2.JSON;
import com.wzw.Command;
import com.wzw.CommandType;
import com.wzw.Result;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {/*** 处理接收到的 TextWebSocketFrame 消息* @param channelHandlerContext 表示当前通道的上下文，包含与通道相关的所有信息和操作方法。*                              可用于执行如写数据、关闭通道、触发事件等操作。* @param textWebSocketFrame    表示接收到的 WebSocket 文本帧消息。*                              包含客户端发送的具体数据内容，可以通过其方法（如 text()）获取消息内容并进行处理。* @throws Exception*/@Overrideprotected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {try {//收到的消息转为Command对象Command command = JSON.parseObject(textWebSocketFrame.text(), Command.class);//判断消息是不是连接登陆switch (CommandType.getCommandType(command.getCode())){case CONNECTION -> ConnectionHandler.execute(channelHandlerContext, command);default -> channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}} catch (Exception e) {channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}}
}

6. 前端代码

<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>简单聊天页面</title><style>body { font-family: Arial, sans-serif; margin: 20px; display: flex; }#leftPanel { width: 30%; padding-right: 20px; box-sizing: border-box; }#rightPanel { width: 70%; }#chatBox { width: 100%; height: 300px; border: 1px solid #ccc; overflow-y: auto; padding: 10px; text-align: left; }#messageInput { width: 80%; padding: 8px; margin-top: 10px; }button { padding: 8px; cursor: pointer; }#nameInput { width: 80%; padding: 8px; margin-top: 10px; }</style>
</head>
<body><div id="leftPanel"><h2>登录</h2><input type="text" id="nameInput" placeholder="输入昵称..."><button id="sign">登陆</button></div><div id="rightPanel"><h2>对话</h2><div id="chatBox"></div><input type="text" id="messageInput" placeholder="输入消息..."><button id="sendBtn">发送</button>
</div><script>let socket;// 监听“登陆”按钮点击document.getElementById("sign").addEventListener("click", function () {// 获取昵称输入框的值const name = document.getElementById("nameInput").value.trim();if (!name) {appendMessage("❌ 请输入昵称");return;}// 连接 WebSocket 服务器socket = new WebSocket("ws://localhost:8001");// 监听 WebSocket 错误socket.onerror = function (error) {console.error("WebSocket 连接错误: ", error);appendMessage("连接服务器异常");};// 监听 WebSocket 连接socket.onopen = function () {console.log("WebSocket 已连接");// 将昵称包含在初始消息中socket.send(JSON.stringify({"code": 1002,"name": name}));};// 监听收到的消息socket.onmessage = function (event) {const data = JSON.parse(event.data);const message = data.message;appendMessage(message);};// 监听 WebSocket 关闭socket.onclose = function () {appendMessage("❌ 连接已关闭");};});// 监听发送按钮点击document.getElementById("sendBtn").addEventListener("click", function () {sendMessage();});// 监听回车键发送消息document.getElementById("messageInput").addEventListener("keypress", function (event) {if (event.key === "Enter") {sendMessage();}});// 发送消息function sendMessage() {if (socket && socket.readyState === WebSocket.OPEN) {const input = document.getElementById("messageInput");const message = JSON.stringify({"code": 1001,"name": input.value.trim()})socket.send(message);appendMessage("📝 我: " + message);input.value = "";} else {appendMessage("❌ 未连接到服务器，请先登录");}}// 在聊天框中追加消息function appendMessage(text) {const chatBox = document.getElementById("chatBox");const messageElement = document.createElement("p");messageElement.textContent = text;chatBox.appendChild(messageElement);chatBox.scrollTop = chatBox.scrollHeight; // 滚动到底部}
</script></body>
</html>

7. 测试上线
   

实现指定用户私聊

1. 创建消息对象，用来接收发送消息

import lombok.Data;@Data
public class ChatMessage extends Command {/*** 消息类型*/private Integer type;/*** 接收人*/private String target;/*** 消息内容*/private String content;
}

2. CommandType补充一个消息类型，代表发送消息

    /*** 登陆连接*/CONNECTION(1001),/*** 消息*/CHAT(1002),/*** 错误*/ERROR(-1);

3. 加一个枚举，区分私有和群聊消息

import lombok.AllArgsConstructor;
import lombok.Getter;@Getter
@AllArgsConstructor
public enum MessageType {PRIVATE(1),GROUP(2),Error(-1);private Integer type;public static MessageType getMessageType(Integer type) {for (MessageType messageType : values()) {if (messageType.getType().equals(type)) {return messageType;}}return Error;}
}

4. 消息处理类

import cn.hutool.core.util.StrUtil;
import com.alibaba.fastjson2.JSON;
import com.wzw.Result;
import com.wzw.command.ChatMessage;
import com.wzw.command.MessageType;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;import static com.wzw.ImServer.USERS;public class ChatHandler {/*** 处理接收到的WebSocket文本消息** @param channelHandlerContext 与客户端通信的ChannelHandlerContext* @param textWebSocketFrame 接收到的WebSocket文本帧*/public static void execute(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) {try {// 将接收到的文本消息解析为ChatMessage对象ChatMessage chatMessage = JSON.parseObject(textWebSocketFrame.text(), ChatMessage.class);// 根据消息类型进行处理switch (MessageType.getMessageType(chatMessage.getType())) {case PRIVATE -> {// 如果目标用户为空，发送失败消息if (StrUtil.isBlank(chatMessage.getTarget())) {channelHandlerContext.channel().writeAndFlush(Result.fail("消息发送失败，请指定消息接收对象"));return;}// 获取目标用户的ChannelChannel channel = USERS.get(chatMessage.getTarget());// 如果目标用户不在线，发送失败消息if (channel == null) {channelHandlerContext.channel().writeAndFlush(Result.fail("消息发送失败，用户" + chatMessage.getTarget() + "不在线"));} else {// 目标用户在线，发送私聊消息channel.writeAndFlush(Result.success("私聊消息（" + chatMessage.getName() + ")：" + chatMessage.getContent()));}}default -> {// 如果消息类型不支持，发送失败消息channelHandlerContext.channel().writeAndFlush(Result.fail("消息发送失败，不支持的消息类型"));}}} catch (Exception e) {// 捕获并处理解析消息时的异常，发送格式错误消息channelHandlerContext.channel().writeAndFlush(Result.fail("消息格式错误"));}}
}

5. WebSocketHandler中新增一个聊天消息处理调用

    @Overrideprotected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {try {Command command = JSON.parseObject(textWebSocketFrame.text(), Command.class);switch (CommandType.getCommandType(command.getCode())){case CONNECTION -> ConnectionHandler.execute(channelHandlerContext, command);//聊天消息处理case CHAT -> ChatHandler.execute(channelHandlerContext, textWebSocketFrame);default -> channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}} catch (Exception e) {channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}}

6. 前端代码

<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>简单聊天页面</title><style>body { font-family: Arial, sans-serif; margin: 20px; display: flex; }#leftPanel { width: 30%; padding-right: 20px; box-sizing: border-box; }#rightPanel { width: 70%; }#chatBox { width: 100%; height: 300px; border: 1px solid #ccc; overflow-y: auto; padding: 10px; text-align: left; }#messageInput { width: 80%; padding: 8px; margin-top: 10px; }button { padding: 8px; cursor: pointer; }#nameInput { width: 80%; padding: 8px; margin-top: 10px; }#targetInput { width: 80%; padding: 8px; margin-top: 10px; }.message { margin: 5px 0; }.message.sent { text-align: right; }.message.received { text-align: left; }.message.sent p { background-color: #e1ffc7; padding: 8px; border-radius: 10px; max-width: 70%; display: inline-block; }.message.received p { background-color: #f0f0f0; padding: 8px; border-radius: 10px; max-width: 70%; display: inline-block; }</style>
</head>
<body><div id="leftPanel"><h2>登录</h2><input type="text" id="nameInput" placeholder="输入昵称..."><button id="sign">登陆</button><h2>接收人</h2><input type="text" id="targetInput" placeholder="输入对方昵称...">
</div><div id="rightPanel"><h2>对话</h2><div id="chatBox"></div><input type="text" id="messageInput" placeholder="输入消息..."><button id="sendBtn">发送好友消息</button>
</div><script>let socket;let myName;// 监听“登陆”按钮点击document.getElementById("sign").addEventListener("click", function () {// 获取昵称输入框的值myName = document.getElementById("nameInput").value.trim();if (!myName) {appendMessage("❌ 请输入昵称", "received");return;}// 连接 WebSocket 服务器socket = new WebSocket("ws://localhost:8001");// 监听 WebSocket 错误socket.onerror = function (error) {console.error("WebSocket 连接错误: ", error);appendMessage("连接服务器异常", "received");};// 监听 WebSocket 连接socket.onopen = function () {console.log("WebSocket 已连接");// 将昵称包含在初始消息中socket.send(JSON.stringify({"code": 1001,"name": myName}));};// 监听收到的消息socket.onmessage = function (event) {const data = JSON.parse(event.data);const message = data.message;const sender = data.name || "服务器";if (sender === myName) {appendMessage("📝 " + sender + ": " + message, "sent");} else {appendMessage("💬 " + sender + ": " + message, "received");}};// 监听 WebSocket 关闭socket.onclose = function () {appendMessage("❌ 连接已关闭", "received");};});// 监听发送按钮点击document.getElementById("sendBtn").addEventListener("click", function () {sendMessage();});// 监听回车键发送消息document.getElementById("messageInput").addEventListener("keypress", function (event) {if (event.key === "Enter") {sendMessage();}});// 发送消息function sendMessage() {if (socket && socket.readyState === WebSocket.OPEN) {const target = document.getElementById("targetInput").value.trim();const input = document.getElementById("messageInput").value.trim();if (!input) {appendMessage("❌ 请输入消息", "received");return;}console.log("发送消息：" + input);const message = JSON.stringify({"code": 1002,"target": target,"name": myName,"type": 1,"content": input});socket.send(message);appendMessage("📝 " + myName + ": " + input, "sent");input.value = "";} else {appendMessage("❌ 未连接到服务器，请先登录", "received");}}// 在聊天框中追加消息function appendMessage(text, type) {const chatBox = document.getElementById("chatBox");const messageElement = document.createElement("div");messageElement.className = "message " + type;const pElement = document.createElement("p");pElement.textContent = text;messageElement.appendChild(pElement);chatBox.appendChild(messageElement);chatBox.scrollTop = chatBox.scrollHeight; // 滚动到底部}
</script></body>
</html>

7. 测试
   

群聊

1. CommandType加入类型

    /*** 加入群聊*/JOIN_GROUP(1003),

2. ImServer新增一个群聊对象

public static final ChannelGroup GROUP = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

3. 修改ChatHandler

    public static void execute(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) {try {// 将接收到的文本消息解析为ChatMessage对象ChatMessage chatMessage = JSON.parseObject(textWebSocketFrame.text(), ChatMessage.class);// 根据消息类型进行处理switch (MessageType.getMessageType(chatMessage.getType())) {case PRIVATE -> {//...}//加入群聊消息发送case GROUP -> ImServer.GROUP.writeAndFlush(Result.success("群聊消息（" + chatMessage.getName() + ")：" + chatMessage.getContent()));default -> {// ...}}} catch (Exception e) {// ...}}

4. 加入群聊JoinFGroupHandler

import com.wzw.ImServer;
import com.wzw.Result;
import io.netty.channel.ChannelHandlerContext;public class JoinFGroupHandler {public static void execute(ChannelHandlerContext channelHandlerContext) {ImServer.GROUP.add(channelHandlerContext.channel());channelHandlerContext.channel().writeAndFlush(Result.success("加入群聊成功"));}
}

5. WebSocketHandler加入处理加入群聊

    @Overrideprotected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {try {Command command = JSON.parseObject(textWebSocketFrame.text(), Command.class);switch (CommandType.getCommandType(command.getCode())){case CONNECTION -> ConnectionHandler.execute(channelHandlerContext, command);case CHAT -> ChatHandler.execute(channelHandlerContext, textWebSocketFrame);//加入群聊处理case JOIN_GROUP -> JoinFGroupHandler.execute(channelHandlerContext);case DISCONNECT -> ConnectionHandler.disconnect(channelHandlerContext,command);default -> channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}} catch (Exception e) {channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}}

6. 前端代码

<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>简单聊天页面</title><style>body { font-family: Arial, sans-serif; margin: 20px; display: flex; }#leftPanel { width: 30%; padding-right: 20px; box-sizing: border-box; }#rightPanel { width: 70%; }#chatBox { width: 100%; height: 300px; border: 1px solid #ccc; overflow-y: auto; padding: 10px; text-align: left; }#messageInput { width: 80%; padding: 8px; margin-top: 10px; }button { padding: 8px; cursor: pointer; }#nameInput { width: 80%; padding: 8px; margin-top: 10px; }#targetInput { width: 80%; padding: 8px; margin-top: 10px; }.message { margin: 5px 0; }.message.sent { text-align: right; }.message.received { text-align: left; }.message.sent p { background-color: #e1ffc7; padding: 8px; border-radius: 10px; max-width: 70%; display: inline-block; }.message.received p { background-color: #f0f0f0; padding: 8px; border-radius: 10px; max-width: 70%; display: inline-block; }</style>
</head>
<body><div id="leftPanel"><h2>登录</h2><input type="text" id="nameInput" placeholder="输入昵称..."><button id="sign">登陆</button><h2>接收人</h2><input type="text" id="targetInput" placeholder="输入对方昵称...">
</div><div id="rightPanel"><h2>对话</h2><div id="chatBox"></div><input type="text" id="messageInput" placeholder="输入消息..."><button id="sendPrivateBtn">发送好友消息</button><button id="sendGroupBtn">发送群消息</button>
</div><script>let socket;let myName;// 监听“登陆”按钮点击document.getElementById("sign").addEventListener("click", function () {// 获取昵称输入框的值myName = document.getElementById("nameInput").value.trim();if (!myName) {appendMessage("❌ 请输入昵称", "received");return;}// 连接 WebSocket 服务器socket = new WebSocket("ws://localhost:8001");// 监听 WebSocket 错误socket.onerror = function (error) {console.error("WebSocket 连接错误: ", error);appendMessage("连接服务器异常", "received");};// 监听 WebSocket 连接socket.onopen = function () {console.log("WebSocket 已连接");// 上线socket.send(JSON.stringify({"code": 1001,"name": myName}));// 加入群聊socket.send(JSON.stringify({"code": 1003,"name": myName}));};// 监听收到的消息socket.onmessage = function (event) {const data = JSON.parse(event.data);const message = data.message;const sender = data.name || "服务器";if (sender === myName) {appendMessage("📝 " + sender + ": " + message, "sent");} else {appendMessage("💬 " + sender + ": " + message, "received");}};// 监听 WebSocket 关闭socket.onclose = function () {appendMessage("❌ 连接已关闭", "received");};});// 监听发送按钮点击document.getElementById("sendPrivateBtn").addEventListener("click", function () {sendPrivateMessage();});// 监听发送按钮点击document.getElementById("sendGroupBtn").addEventListener("click", function () {sendGroupMessage();});// 监听回车键发送消息document.getElementById("messageInput").addEventListener("keypress", function (event) {if (event.key === "Enter") {sendPrivateMessage();}});// 发送私聊消息function sendPrivateMessage() {if (socket && socket.readyState === WebSocket.OPEN) {const target = document.getElementById("targetInput").value.trim();const input = document.getElementById("messageInput").value.trim();if (!input) {appendMessage("❌ 请输入消息", "received");return;}console.log("发送消息：" + input);const message = JSON.stringify({"code": 1002,"target": target,"name": myName,"type": 1,"content": input});socket.send(message);appendMessage("📝 " + myName + ": " + input, "sent");input.value = "";} else {appendMessage("❌ 未连接到服务器，请先登录", "received");}}// 发送群消息function sendGroupMessage() {if (socket && socket.readyState === WebSocket.OPEN) {const target = document.getElementById("targetInput").value.trim();const input = document.getElementById("messageInput").value.trim();if (!input) {appendMessage("❌ 请输入消息", "received");return;}console.log("发送消息：" + input);const message = JSON.stringify({"code": 1002,"target": target,"name": myName,"type": 2,"content": input});socket.send(message);appendMessage("📝 " + myName + ": " + input, "sent");input.value = "";} else {appendMessage("❌ 未连接到服务器，请先登录", "received");}}// 在聊天框中追加消息function appendMessage(text, type) {const chatBox = document.getElementById("chatBox");const messageElement = document.createElement("div");messageElement.className = "message " + type;const pElement = document.createElement("p");pElement.textContent = text;messageElement.appendChild(pElement);chatBox.appendChild(messageElement);chatBox.scrollTop = chatBox.scrollHeight; // 滚动到底部}// 监听窗口关闭事件window.addEventListener("beforeunload", function () {if (socket && socket.readyState === WebSocket.OPEN) {const message = JSON.stringify({"code": 1000,"name": myName});socket.send(message);socket.close();}});
</script></body>
</html>

7. 效果
   

离线

1. 离线的代码实现

    /*** 断开* @param channelHandlerContext* @param command*/public static void disconnect(ChannelHandlerContext channelHandlerContext, Command command) {ImServer.USERS.remove(command.getName());channelHandlerContext.disconnect();}

2. 调用离线方法

    @Overrideprotected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {try {Command command = JSON.parseObject(textWebSocketFrame.text(), Command.class);switch (CommandType.getCommandType(command.getCode())){case CONNECTION -> ConnectionHandler.execute(channelHandlerContext, command);case CHAT -> ChatHandler.execute(channelHandlerContext, textWebSocketFrame);//离线case DISCONNECT -> ConnectionHandler.disconnect(channelHandlerContext,command);default -> channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}} catch (Exception e) {channelHandlerContext.channel().writeAndFlush(Result.fail("未知指令"));}}

3. 前端代码，关闭页面的时候，断开连接

    // 监听窗口关闭事件window.addEventListener("beforeunload", function () {if (socket && socket.readyState === WebSocket.OPEN) {const message = JSON.stringify({"code": 1000,"name": myName});socket.send(message);socket.close();}});

SpringBoot+WebSocket+Html+jQuery实现客服聊天

已经实现客户功能，支持多人会话聊天、交互，如果需要保存聊天记录，自己实现，保存到数据库即可。

1. 目录结构

2. 配置类

• CorsConfig

package com.wzw.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class CorsConfig {@Beanpublic WebMvcConfigurer corsConfigurer() {return new WebMvcConfigurer() {@Overridepublic void addCorsMappings(CorsRegistry registry) {registry.addMapping("/**")  // 允许所有路径.allowedOrigins("*")  // 允许所有域.allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")  // 允许的请求方法.allowedHeaders("*")  // 允许的请求头.allowCredentials(false);  // 不允许携带 Cookie}};}
}

• RedisConfig

package com.wzw.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;@Configuration
public class RedisConfig {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {RedisTemplate<String, Object> template = new RedisTemplate<>();template.setConnectionFactory(connectionFactory);// 配置 key 的序列化方式template.setKeySerializer(new StringRedisSerializer());// 配置 value 的序列化方式，这里使用 Jackson 来序列化对象为 JSON 格式template.setValueSerializer(new GenericJackson2JsonRedisSerializer());// 同样地配置 Hash 类型的 key 和 value 的序列化方式template.setHashKeySerializer(new StringRedisSerializer());template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());// 初始化序列化配置template.afterPropertiesSet();return template;}}

• WebSocketConfig

package com.wzw.config;  // 包声明，定义配置类所在的包路径import com.wzw.handler.ChatWebSocketHandler;  // 导入处理WebSocket消息的处理器类
import org.springframework.context.annotation.Configuration;  // Spring配置类注解
import org.springframework.web.socket.config.annotation.EnableWebSocket;  // 启用WebSocket支持
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;  // WebSocket配置接口
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;  // WebSocket处理器注册类@Configuration  // 声明这是一个Spring配置类
@EnableWebSocket  // 启用WebSocket功能
public class WebSocketConfig implements WebSocketConfigurer {  // 实现WebSocket配置接口private final ChatWebSocketHandler chatWebSocketHandler;  // 注入处理WebSocket消息的处理器实例// 构造函数，通过依赖注入获取ChatWebSocketHandler实例public WebSocketConfig(ChatWebSocketHandler chatWebSocketHandler) {this.chatWebSocketHandler = chatWebSocketHandler;}@Overridepublic void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {// 注册WebSocket处理器，配置连接路径和跨域设置registry.addHandler(chatWebSocketHandler, "/chat")  // 将处理器绑定到路径 "/chat".setAllowedOrigins("*");  // 允许所有来源的跨域请求（生产环境建议限制具体域名）}
}

3. 实体类、service、controller

• ChatMessage

package com.wzw.entity;import lombok.Data;@Data
public class ChatMessage {/*** 类型*      session 连接成功*      join    加入会话*/private String type;private String sessionId;/*** 发送者*/private String from;/*** 发送者昵称*/private String fromName;/*** 接收者*/private String to;/*** 消息内容*/private String message;
}

• ChatService

package com.wzw.service;import com.alibaba.fastjson2.JSON;
import com.wzw.entity.ChatMessage;
import com.wzw.handler.ChatWebSocketHandler;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;import java.io.IOException;
import java.util.*;
import java.util.concurrent.atomic.AtomicReference;@Service
public class ChatService {/*** 所有会话* @return*/public Map<String, Object> chatAll(String sessionId) {Map<String, Object> map = new HashMap<>();ChatWebSocketHandler.chatSessions.forEach((key, value) -> {List<String> users=new ArrayList<>();if(!key.equals(sessionId)){value.forEach((k, v) -> {users.add(ChatWebSocketHandler.getUserIdFromSession(v));});map.put(key, users);}});return map;}/*** 加入会话* @param chatMessage* @return*/public Map<String, Object> join(ChatMessage chatMessage) {Map<String, Map<String, WebSocketSession>> chatSessions = ChatWebSocketHandler.chatSessions;Map<String,Object> result=new HashMap<>();chatSessions.forEach((key, value) -> {if (key.equals(chatMessage.getTo())) {//找到要加入的目标会话Map<String, WebSocketSession> map = new HashMap<>(chatSessions.get(chatMessage.getTo()));//找到来源会话信息Map<String, WebSocketSession> map1 = new HashMap<>(chatSessions.get(chatMessage.getFrom()));AtomicReference<String> user= new AtomicReference<>("");map.forEach((k, v) -> {user.set(ChatWebSocketHandler.getUserIdFromSession(v));try {chatMessage.setFromName("系统消息");chatMessage.setSessionId(chatMessage.getTo());chatMessage.setType("join");chatMessage.setMessage(ChatWebSocketHandler.getUserIdFromSession(map1.get(chatMessage.getFrom()))+"加入会话");v.sendMessage(new TextMessage(JSON.toJSONString(chatMessage)));} catch (IOException e) {throw new RuntimeException(e);}});//将来源会话加入到要加入的目标会话中map.putAll(map1);chatSessions.put(key, map);result.put("1","加入群聊成功");result.put("to",user);}});return CollectionUtils.isEmpty(result)?Map.of("-1","加入群聊失败"):result;}/*** 断开会话* @param chatMessage* @return*/public Map<String, Object> disconnect(ChatMessage chatMessage) {Map<String, Map<String, WebSocketSession>> chatSessions = ChatWebSocketHandler.chatSessions;Map<String,Object> result = new HashMap<>();// 遍历外层MapchatSessions.forEach((key, value) -> {if (key.equals(chatMessage.getTo())) {value.forEach((k, v) -> {// 创建可变副本进行操作Map<String, WebSocketSession> mutableMap = new HashMap<>(value);mutableMap.remove(chatMessage.getFrom()); // 安全删除// 更新原始Map（需同步处理）chatSessions.put(key, mutableMap);result.put("1", "成功断开会话: " + chatMessage.getFrom());});}});return CollectionUtils.isEmpty(result) ?Collections.singletonMap("-1", "断开会话失败") : result;}}

• ChatController

package com.wzw.controller;import com.wzw.entity.ChatMessage;
import com.wzw.service.ChatService;
import jakarta.annotation.Resource;
import org.springframework.web.bind.annotation.*;import java.util.Map;@RestController
@RequestMapping("/chat")
public class ChatController {@Resourceprivate ChatService chatService;/*** 所有会话* @param sessionId* @return*/@GetMapping("/list")public Map<String, Object> chat(String sessionId) {return chatService.chatAll(sessionId);}/*** 加入会话* @param chatMessage* @return*/@PostMapping("/join")public Map<String, Object> join(@RequestBody ChatMessage chatMessage) {return chatService.join(chatMessage);}/*** 退出会话* @param chatMessage* @return*/@PostMapping("/disconnect")public Map<String, Object> disconnect(@RequestBody ChatMessage chatMessage) {return chatService.disconnect(chatMessage);}}

4. ChatWebSocketHandler消息处理

package com.wzw.handler;  // 定义包路径import com.alibaba.fastjson2.JSON;  // JSON序列化/反序列化工具
import com.wzw.entity.ChatMessage;  // 聊天消息实体类
import com.wzw.util.RedisUtil;  // Redis工具类（用于缓存操作）
import io.netty.channel.group.ChannelGroup;  // Netty通道组（用于管理WebSocket连接）
import io.netty.channel.group.DefaultChannelGroup;  // 默认通道组实现
import io.netty.util.concurrent.GlobalEventExecutor;  // Netty全局事件执行器
import jakarta.annotation.Resource;  // Spring依赖注入注解
import lombok.extern.slf4j.Slf4j;  // 日志记录工具
import org.springframework.stereotype.Component;  // Spring组件注解
import org.springframework.web.socket.*;  // WebSocket相关接口和类
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;@Slf4j  // 启用日志记录
@Component  // 声明为Spring组件
public class ChatWebSocketHandler implements WebSocketHandler {  // 实现WebSocket处理器接口// 存储所有会话的静态Map：外层Key为会话ID，内层Key为用户Session IDpublic static Map<String, Map<String, WebSocketSession>> chatSessions = new HashMap<>();@Resource  // Spring依赖注入Redis工具类private RedisUtil redisUtil;// WebSocket连接建立时触发@Overridepublic void afterConnectionEstablished(WebSocketSession session) throws Exception {// 从会话中获取用户ID（通过URL参数）String userId = getUserIdFromSession(session);// 将当前会话存入chatSessions（外层Key为session.getId()）chatSessions.put(session.getId(), Map.of(session.getId(), session));// 构建系统消息通知用户连接成功ChatMessage chatMessage = new ChatMessage();chatMessage.setFromName("系统消息");chatMessage.setMessage("连接成功");chatMessage.setFrom(userId);chatMessage.setSessionId(session.getId());chatMessage.setType("session");// 将消息发送给当前用户session.sendMessage(new TextMessage(JSON.toJSONString(chatMessage)));// 将用户ID存入Redis（示例用途，可能用于会话关联）redisUtil.set("a", userId);log.info("用户连接: {}", userId);}// 处理会话消息@Overridepublic void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {// 获取原始消息内容（JSON字符串）String payload = message.getPayload().toString();// 将JSON反序列化为ChatMessage对象ChatMessage chatMessage = JSON.parseObject(payload, ChatMessage.class);log.info("收到消息: {}", payload);// 根据消息目标会话ID获取目标会话集合Map<String, WebSocketSession> map = chatSessions.get(chatMessage.getTo());// 遍历目标会话中的所有用户map.forEach((key, value) -> {if (value.isOpen()) {  // 检查会话是否处于打开状态try {// 将消息广播给目标会话的所有用户value.sendMessage(new TextMessage(payload));} catch (IOException e) {log.error("发送消息失败", e);}}});}// 处理WebSocket传输错误@Overridepublic void handleTransportError(WebSocketSession session, Throwable exception) {log.error("WebSocket错误", exception);}// WebSocket连接关闭时触发@Overridepublic void afterConnectionClosed(WebSocketSession session, CloseStatus status) {// 从chatSessions中移除已关闭的会话chatSessions.remove(session.getId());log.info("用户断开连接: {}", session.getId());}// 是否支持分片消息（通常返回false）@Overridepublic boolean supportsPartialMessages() {return false;}// 从WebSocket会话中提取用户ID（通过URL参数）public static String getUserIdFromSession(WebSocketSession session) {String query = session.getUri().getQuery();  // 获取URL查询参数if (query != null && query.contains("userId=")) {return query.split("userId=")[1];  // 提取userId参数值}return "anonymous-" + session.getId();  // 若未找到参数，生成匿名ID}
}

5.前端页面

<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>客服界面</title><style>body {font-family: Arial, sans-serif;background-color: #f4f4f9;margin: 0;padding: 20px;display: flex;}.left-container, .right-container {flex: 1;padding: 10px;}.left-container {margin-right: 20px;}h2 {color: #333;}#chatBox {border: 1px solid #ccc;width: 100%;height: 300px;overflow-y: auto;background-color: #fff;padding: 10px;border-radius: 8px;margin-bottom: 10px;}#messageInput {width: calc(100% - 110px);padding: 10px;border: 1px solid #ccc;border-radius: 4px;margin-right: 10px;}#sendButton {padding: 10px 20px;border: none;background-color: #007bff;color: #fff;border-radius: 4px;cursor: pointer;}#sendButton:hover {background-color: #0056b3;}.message {margin: 10px 0;padding: 0 6px;border-radius: 10px;max-width: 70%;word-wrap: break-word;clear: both; /* 确保每条消息独占一行 */}.message.sent {background-color: #a9f3a9;color: #000000;float: right;}.message.received {background-color: #ccc;color: black;float: left;}.center-message {display: block;text-align: center; /* 确保水平居中 */margin: 10px 0;padding: 0 6px;border-radius: 10px;max-width: 100%;word-wrap: break-word;background-color: #f0f0f0;color: #333;clear: both; /* 确保系统消息和加入聊天提示独占一行 */}.input-container {display: flex;width: 100%;}#messageInput {flex: 1;}#chatList {border: 1px solid #ccc;background-color: #fff;padding: 10px;border-radius: 8px;height: 200px;overflow-y: auto;}#chatList table {width: 100%;border-collapse: collapse;}#chatList th, #chatList td {border: 1px solid #ddd;padding: 8px;text-align: left;}#chatList th {background-color: #f2f2f2;}#chatList button {padding: 5px 10px;border: none;background-color: #007bff;color: #fff;border-radius: 4px;cursor: pointer;}#chatList button:hover {background-color: #0056b3;}</style><!-- 引入jQuery库 --><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
<div class="left-container"><button id="fetchChatListButton">获取聊天列表</button><div id="chatList"><table><thead><tr><th>序号</th><th>描述</th><th>操作</th></tr></thead><tbody><!-- 表格行将动态插入到这里 --></tbody></table></div>
</div>
<div class="right-container"><h2>客服聊天</h2><p>你的 ID: <span id="userId"></span></p><div id="chatBox"></div><div class="input-container"><input type="text" id="messageInput" placeholder="输入消息"><button id="sendButton">发送</button></div>
</div><script>$(document).ready(function() {const userId = "agent-" + Math.random().toString(36).substring(7);let sessionId = null;let toSessionId = null;$("#userId").text(userId);const socket = new WebSocket("ws://localhost:8080/chat?userId=" + userId);socket.onopen = function () {console.log("WebSocket 已连接");};socket.onmessage = function (event) {const data = JSON.parse(event.data);if(data.type==="session"){sessionId=data.sessionId;}if(data.from!==sessionId){addMessageToChatBox(data.fromName, data.message, "received");}};socket.onerror = function (error) {console.error("WebSocket 发生错误:", error);};$("#sendButton").click(function() {const message = $("#messageInput").val();const toUserId = $("#toUserId").val();const chatMessage = {from: sessionId,to: toSessionId,fromName: userId,message: message};console.log(chatMessage);socket.send(JSON.stringify(chatMessage));addMessageToChatBox(userId, message, "sent");$("#messageInput").val("");});$("#fetchChatListButton").click(function() {$.ajax({url: 'http://127.0.0.1:8080/chat/list?sessionId='+sessionId,method: 'GET',success: function(data) {const chatList = $("#chatList tbody");chatList.empty(); // 清空表格let index = 1;for (const [key, value] of Object.entries(data)) {const tr = $(`<tr><td>${index}</td><td>${value}</td><td><button class="joinButton" data-key="${key}">加入</button></td></tr>`);toSessionId=key;chatList.append(tr);index++;}},error: function(error) {console.error("获取聊天列表失败:", error);}});});$(document).on("click", ".joinButton", function() {const key = $(this).data("key");$.ajax({url: 'http://127.0.0.1:8080/chat/join',method: 'POST',contentType: 'application/json',data: JSON.stringify({to: key,from: sessionId}),success: function(response) {console.log("加入聊天成功:", response);addMessageToChatBox("系统消息", `已成功加入 ${response.to} 聊天`, "center");},error: function(error) {console.error("加入聊天失败:", error);addMessageToChatBox("系统消息", "加入聊天失败，请重试", "center");}});});// 新增函数：添加消息到聊天框function addMessageToChatBox(fromName, message, type) {const messageElement = $(`<div class="message ${type}"><p><b>${fromName}:</b> ${message}</p></div>`);$("#chatBox").append(messageElement);$("#chatBox").scrollTop($("#chatBox")[0].scrollHeight);}});
</script>
</body>
</html>

6.效果

会话列表：只要访问页面，就会创建一个会话。目前需要手动刷新，如果有人加入，描述中会出现此会话，显示所有参与人的昵称。
加入会话：只能加入一个会话，如果已经加入过其它会话，会断开上一个加入的会话，然后加入新的会话中。
聊天框：绿色是自己发出的消息，左边灰色是收到的消息，中间是系统消息

如果有人加入了你当前的会话，会出现提示，直接发送消息，加入会话中的人都可以看到

代码链接

所有代码链接：https://gitee.com/w452339689/im.git