爱站程序员基地websocket 概念
websocket 是一个通信协议，通过单个 TCP 连接提供全双工通信。websocket 连接成功后，服务端和客户可以进行双向通信。不同于 http 通信协议需要每次由客户端发起，服务响应到客户端。websocket 相对轮询也能节约带宽，并且能实时的进行通信。
整合步骤
1. 添加 maven 依赖
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-websocket</artifactId><version>2.1.3.RELEASE</version></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-freemarker</artifactId><version>2.1.3.RELEASE</version></dependency>
添加web、websocket和freemarker依赖。
2. 使用 ServerEndpointExporter 创建 bean
这个 bean 会自动注册声明 @ServerEndpoint 注解声明的 websocket endpoint，使用springboot自带tomcat启动需要该配置，使用独立 tomcat 则不需要该配置。
@Configurationpublic class WebSocketConfig {//tomcat启动无需该配置@Beanpublic ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();}}
3. 创建服务端端点 (ServerEndpoint)
@Component@ServerEndpoint(value = "/message")@Slf4jpublic class WebSocket {private static Map<String, WebSocket> webSocketSet = new ConcurrentHashMap<>();private Session session;@OnOpenpublic void onOpen(Session session) throws SocketException {this.session = session;webSocketSet.put(this.session.getId(),this);log.info("【websocket】有新的连接,总数:{}",webSocketSet.size());}@OnClosepublic void onClose(){String id = this.session.getId();if (id != null){webSocketSet.remove(id);log.info("【websocket】连接断开:总数:{}",webSocketSet.size());}}@OnMessagepublic void onMessage(String message){if (!message.equals("ping")){log.info("【wesocket】收到客户端发送的消息,message={}",message);sendMessage(message);}}/*** 发送消息* @param message* @return 全部都发送一遍*/public void sendMessage(String message){for (WebSocket webSocket : webSocketSet.values()) {webSocket.session.getAsyncRemote().sendText(message);}log.info("【wesocket】广播消息,message={}", message);}}
4. 添加 controller 和 客户端
- 添加 controller
@GetMapping({"","index.html"})public ModelAndView index() {ModelAndView view = new ModelAndView("index");return view;}
- 添加ftl页面
<!DOCTYPE html><html><head><title>websocket</title></head><body><div><input type="text" name="message" id="message"><button id="sendBtn">发送</button></div><div style="width:100px;height: 500px;" id="content"></div><script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.js"></script><script type="text/javascript">var ws = new WebSocket("ws://127.0.0.1:8080/message");ws.onopen = function(evt) {console.log("Connection open ...");};ws.onmessage = function(evt) {console.log( "Received Message: " + evt.data);var p = $("<p>"+evt.data+"</p>")$("#content").prepend(p);$("#message").val("");};ws.onclose = function(evt) {console.log("Connection closed.");};$("#sendBtn").click(function(){var aa = $("#message").val();ws.send(aa);})</script></body></html>
5. 展示效果
附录
github源码
