本示例实现一个功能,前端通过websocket发送消息给后端服务,后端服务接收到该消息时,原样将消息返回给前端。前端技术栈html+stomp.js,后端SpringBoot
前端代码
关于stomp客户端的开发,如果不清楚的,可以看一下上一篇文章
这里我对Stomp.js进行了一个简单的封装,写在stomp-client.js里面
/*** 对 stomp 客户端进行封装*/var client;
var subscribes = [];
var errorTimes = 0;var endpoint = "/ws";/*** 建立websocket连接* @param {Function} onConnecting 开始连接时的回调* @param {Function} onConnected 连接成功回调* @param {Function} onError 连接异常或断开回调*/
function connect(onConnecting, onConnected, onError) {onConnecting instanceof Function && onConnecting();var sock = new SockJS(endpoint);client = Stomp.over(sock);console.log("ws: start connect to " + endpoint);client.connect({}, function (frame) {errorTimes = 0;console.log('connected: ' + frame);// 连接成功后重新订阅subscribes.forEach(function (item) {client.subscribe(item.destination, function (resp) {console.debug("ws收到消息: ", resp);item.cb(JSON.parse(resp.body));});});onConnected instanceof Function && onConnected();}, function (err) {errorTimes = errorTimes > 8 ? 0 : errorTimes;var nextTime = ++errorTimes * 3000;console.warn("与服务器断开连接," + nextTime + " 秒后重新连接", err);setTimeout(function () {console.log("尝试重连……");connect(onConnecting, onConnected, onError);}, nextTime);onError instanceof Function && onError();});
}/*** 订阅消息,若当前未连接,则会在连接成功后自动订阅** 注意,为防止重连导致重复订阅,请勿使用匿名函数做回调** @param {String} destination 目标* @param {Function} cb 回调*/
function subscribe(destination, cb) {var exist = subscribes.filter(function (sub) {return sub.destination === destination && sub.cb === cb});// 防止重复订阅if (exist && exist.length) {return;}// 记录所有订阅,在连接成功时统一处理subscribes.push({destination: destination,cb: cb});if (client && client.connected) {client.subscribe(destination, function (resp) {console.debug("ws收到消息: ", resp);cb instanceof Function && cb(JSON.parse(resp.body));});} else {console.warn("ws未连接,暂时无法订阅:" + destination)}
}/*** 发送消息* @param {String} destination 目标* @param {Object} msg 消息体对象*/
function send(destination, msg) {if (!client) {console.error("客户端未连接,无法发送消息!")}client.send(destination, {}, JSON.stringify(msg));
}window.onbeforeunload = function () {// 当窗口关闭时断开连接if (client && client.connected) {client.disconnect(function () {console.log("websocket disconnected ");});}
};
前端的html页面index.html如下:
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>STOMP</title>
</head>
<body>
<h1 id="tip">Welcome!</h1>
<p>状态: <span id="status"></span></p>
<input type="text" id="content" placeholder="请输入要发送的消息"> <br>
<button onclick="sendTextMsg()">发送</button>
<ul id="ul">
</ul>
<script th:src="@{lib/sockjs.min.js}"></script>
<script th:src="@{lib/stomp.min.js}"></script>
<script th:src="@{stomp-client.js}"></script>
<script>connect(function () {statusChange("连接中...");}, function () {statusChange("在线");// 注意,为防止重连导致重复订阅,请勿使用匿名函数做回调subscribe("/user/topic/subNewMsg", onNewMsg);}, function () {statusChange("离线");});function onNewMsg(msg) {var li = document.createElement("li");li.innerText = msg.content;document.getElementById("ul").appendChild(li);}function sendTextMsg() {var content = document.getElementById("content").value;var msg = {msgType: 1,content: content};send("/app/echo", msg);}function statusChange(status) {document.getElementById("status").innerText = status;}
</script>
</body>
</html>
后端代码
依赖引入,主要引入下面的包,其它的包略过
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-websocket</artifactId></dependency>
配置类
@Slf4j
@Setter
@Configuration
@EnableWebSocketMessageBroker
@ConfigurationProperties(prefix = "websocket")
@RequiredArgsConstructor(onConstructor_ = {@Autowired})
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer, ApplicationListener<BrokerAvailabilityEvent> {private final BrokerConfig brokerConfig;private String[] allowOrigins;@Overridepublic void registerStompEndpoints(StompEndpointRegistry registry) {// 继承DefaultHandshakeHandler并重写determineUser方法,可以自定义如何确定用户// 添加方法:registry.addEndpoint("/ws").setHandshakeHandler(handshakeHandler)registry.addEndpoint("/ws").setAllowedOrigins(allowOrigins).withSockJS();}/*** 配置消息代理*/@Overridepublic void configureMessageBroker(MessageBrokerRegistry registry) {registry.setApplicationDestinationPrefixes("/app");if (brokerConfig.isUseSimpleBroker()) {// 使用 SimpleBroker// 配置前缀, 有这些前缀的消息会路由到brokerregistry.enableSimpleBroker("/topic", "/queue")//配置stomp协议里, server返回的心跳.setHeartbeatValue(new long[]{10000L, 10000L})//配置发送心跳的scheduler.setTaskScheduler(new DefaultManagedTaskScheduler());} else {// 使用外部 Broker// 指定前缀,有这些前缀的消息会路由到brokerregistry.enableStompBrokerRelay("/topic", "/queue")// 广播用户目标,如果要推送的用户不在本地,则通过 broker 广播给集群的其他成员.setUserDestinationBroadcast("/topic/log-unresolved-user")// 用户注册广播,一旦有用户登录,则广播给集群中的其他成员.setUserRegistryBroadcast("/topic/log-user-registry")// 虚拟地址.setVirtualHost(brokerConfig.getVirtualHost())// 用户密码.setSystemLogin(brokerConfig.getUsername()).setSystemPasscode(brokerConfig.getPassword()).setClientLogin(brokerConfig.getUsername()).setClientPasscode(brokerConfig.getPassword())// 心跳间隔.setSystemHeartbeatSendInterval(10000).setSystemHeartbeatReceiveInterval(10000)// 使用 setTcpClient 以配置多个 broker 地址,setRelayHost/Port 只能配置一个.setTcpClient(createTcpClient());}}/*** 创建 TcpClient 工厂,用于配置多个 broker 地址*/private ReactorNettyTcpClient<byte[]> createTcpClient() {return new ReactorNettyTcpClient<>(// BrokerAddressSupplier 用于获取中继地址,一次只使用一个,如果该中继出错,则会获取下一个client -> client.addressSupplier(brokerConfig.getBrokerAddressSupplier()),new StompReactorNettyCodec());}@Overridepublic void onApplicationEvent(BrokerAvailabilityEvent event) {if (!event.isBrokerAvailable()) {log.warn("stomp broker is not available!!!!!!!!");} else {log.info("stomp broker is available");}}
}
消息处理
@Slf4j
@Controller
@RequiredArgsConstructor(onConstructor_ = {@Autowired})
public class StompController {private final SimpMessageSendingOperations msgOperations;private final SimpUserRegistry simpUserRegistry;/*** 回音消息,将用户发来的消息内容加上 Echo 前缀后推送回客户端*/@MessageMapping("/echo")public void echo(Principal principal, Msg msg) {String username = principal.getName();msg.setContent("Echo: " + msg.getContent());msgOperations.convertAndSendToUser(username, "/topic/subNewMsg", msg);int userCount = simpUserRegistry.getUserCount();int sessionCount = simpUserRegistry.getUser(username).getSessions().size();log.info("当前本系统总在线人数: {}, 当前用户: {}, 该用户的客户端连接数: {}", userCount, username, sessionCount);}
}
实现效果
报文分析
开启调试模式,我们根据报文来分析一下前后端互通的报文
握手
客户端请求报文如下
GET ws://localhost:8025/ws/035/5hy4avgm/websocket HTTP/1.1
Host: localhost:8025
Connection: Upgrade
Pragma: no-cache
Cache-Control: no-cache
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.5735.289 Safari/537.36
Upgrade: websocket
Origin: http://localhost:8025
Sec-WebSocket-Version: 13
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Cookie: 略
Sec-WebSocket-Key: PlMHmdl2JRzDAVk3feOaeA==
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
服务端响应握手请求
HTTP/1.1 101
Upgrade: websocket
Connection: upgrade
Sec-WebSocket-Accept: 9CKY8n1j/cHoKsWmpmX4pNlQuZg=
Sec-WebSocket-Extensions: permessage-deflate;client_max_window_bits=15
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Frame-Options: DENY
Date: Thu, 08 Feb 2024 06:58:28 GMT
stomp报文分析
在浏览器消息一栏,我们可以看到长连接过程中通信的报文
下面来简单分析一下stomp的报文
客户端请求连接
其中\n表示换行
["CONNECT\naccept-version:1.1,1.0\nheart-beat:10000,10000\n\n\u0000"
]
可以看到请求连接的命令是CONNECT,连接报文里面还包含了心跳的信息
服务端返回连接成功
["CONNECTED\nversion:1.1\nheart-beat:10000,10000\nuser-name:admin\n\n\u0000"
]
CONNECTED是服务端连接成功的命令,报文中也包含了心跳的信息
客户端订阅
订阅的目的地是:/user/topic/subNewMsg
["SUBSCRIBE\nid:sub-0\ndestination:/user/topic/subNewMsg\n\n\u0000"]
客户端发送消息
发送的目的地是:/app/echo
["SEND\ndestination:/app/echo\ncontent-length:35\n\n{\"msgType\":1,\"content\":\"你好啊\"}\u0000"
]
服务端响应消息
响应的目的地是:/user/topic/subNewMsg,当订阅了这个目的地的,方法,将会被回调
["MESSAGE\ndestination:/user/topic/subNewMsg\ncontent-type:application/json;charset=UTF-8\nsubscription:sub-0\nmessage-id:5hy4avgm-1\ncontent-length:41\n\n{\"content\":\"Echo: 你好啊\",\"msgType\":1}\u0000"
]
心跳报文
可以看到,约每隔10S,客户端和服务端都有一次心跳报文,发送的报文内容为一个回车。
[\n]
项目链接:https://gitee.com/syk1234/stomp-demo.git