引入依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

核心代码

/**
 * 
 * webSocket服务端
 */
@Component
@ServerEndpoint("/webSocket")
@Slf4j
public class WebSocket {

    private Session session;
    private static CopyOnWriteArraySet<WebSocket> webSocketSet = new CopyOnWriteArraySet<>();

    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        webSocketSet.add(this);
        log.info("连接数:{}", webSocketSet.size());
    }

    @OnClose
    public void onClose() {
        webSocketSet.remove(this);
        log.info("连接数:{}", webSocketSet.size());
    }

    @OnMessage
    public void onMessage(String message) {
        log.info("收到客户端发来的消息:{}", message);
    }
    public void sendMessage(String message) {
         log.info("广播消息：{}", message);
        for (WebSocket webSocket: webSocketSet) {
            try {
                webSocket.session.getBasicRemote().sendText(message);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

页面代码示例

<script>
    var websocket = null;
    if('WebSocket' in window) {
        websocket = new WebSocket('ws://192.168.186.108:8080/webSocket');
    }else {
        alert('该浏览器不支持websocket');
    }
    websocket.onopen = function (event) {
        console.log('建立连接');
    }
    websocket.onclose = function (event) {
        console.log('连接关闭');
    }
    websocket.onmessage = function (event) {
        console.log('收到消息:' + event.data);
    }
    websocket.onerror = function () {
        console.log('websocket通信发生错误！');
    }
    window.onbeforeunload = function () {
        websocket.close();
    }
</script>