springboot集成websocket需要三步：

• 添加依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
            <version>2.1.6.RELEASE</version>
        </dependency>

 添加配置类

@Configuration
@EnableWebSocket
public class WebSocketConfig {

    @Bean
    public ServerEndpointExporter serverEndpoint() {
        return new ServerEndpointExporter();
    }

}

 添加Websocket监听类

@ServerEndpoint("/webSocket")
@Component
public class WebSocketServer {
    private static AtomicInteger onlineNum = new AtomicInteger();

    private static ConcurrentHashMap<String, Session> sessionPools = new ConcurrentHashMap<>();

    //发送消息
    public void sendMessage(Session session, String message) throws IOException {
        if(session != null){
            synchronized (session) {
                System.out.println("发送数据：" + message);
                session.getBasicRemote().sendText(message);
            }
        }
    }

    //建立连接成功调用
    @OnOpen
    public void onOpen(Session session){
        addOnlineCount();
        System.out.println("加入webSocket！当前人数为" + onlineNum);
        // 广播上线消息
    }

    //关闭连接时调用
    @OnClose
    public void onClose(){
        subOnlineCount();
        System.out.println("断开webSocket连接！当前人数为" + onlineNum);
    }

    //收到客户端信息
    @OnMessage
    public void onMessage(String message) throws IOException{
        System.out.println("server get" + message);
    }

    //错误时调用
    @OnError
    public void onError(Session session, Throwable throwable){
        System.out.println("发生错误");
        throwable.printStackTrace();
    }

    public static void addOnlineCount(){
        onlineNum.incrementAndGet();
    }

    public static void subOnlineCount() {
        onlineNum.decrementAndGet();
    }

    public static AtomicInteger getOnlineNumber() {
        return onlineNum;
    }

    public static ConcurrentHashMap<String, Session> getSessionPools() {
        return sessionPools;
    }
}

用websocket在线测试验证：

websocket在线测试

 控制台接受消息：

 当发送一个超长的文本内容时（超过8kb）出现了以下问题：

 

 发现断开了连接！

接下来我们只需要配置两个参数即可解决：

改造原来的配置类：

@Configuration
@EnableWebSocket
public class WebSocketConfig implements ServletContextInitializer {

    @Bean
    public ServerEndpointExporter serverEndpoint() {
        return new ServerEndpointExporter();
    }

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        servletContext.addListener(WebAppRootListener.class);
        servletContext.setInitParameter("org.apache.tomcat.websocket.textBufferSize","52428800");
        servletContext.setInitParameter("org.apache.tomcat.websocket.binaryBufferSize","52428800");
    }
}

配置org.apache.tomcat.websocket.textBufferSize、org.apache.tomcat.websocket.binaryBufferSize 的值为50M，再进行尝试，success！