关于websocket:SpringBoot整合WebSocket和AOP的问题

背景

最近在我的项目上用了 WebSocket，然而遇到了一个很奇怪的问题，利用启动时抛出

Failed to register @ServerEndpoint class

配置类

package com.smec.fin.config.websocket;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * @Description:
 * @author: wei.wang
 * @since: 2020/7/28 10:29
 * @history: 1.2020/7/28 created by wei.wang
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();
    }
}

接管连贯的类

package com.smec.fin.service.impl;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * @Description:
 * @author: wei.wang
 * @since: 2020/7/28 10:46
 * @history: 1.2020/7/28 created by wei.wang
 */


@ServerEndpoint("/websocket")
@Component
public class WebSocketServer {private static Logger logger = LoggerFactory.getLogger(WebSocketServer.class);

    /**
     * 动态变量，用来记录以后在线连接数。*/
    private static volatile int onlineCount = 0;

    /**
     * concurrent 包的线程平安 Set，用来寄存每个客户端对应的 WebSocket 对象，目前只有一个客户端，所以应用 Set
     */
    private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();


    /**
     * 与某个客户端的连贯会话，须要通过它来给客户端发送数据
     */
    private Session session;


    /**
     * 连贯建设胜利调用的办法
     */
    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        // 退出 set 中
        webSocketSet.add(this);

        // 在线数加 1
        addOnlineCount();
        logger.info("开始监听, 以后在线人数为 {}", getOnlineCount());
    }

    /**
     * 连贯敞开调用的办法
     */
    @OnClose
    public void onClose() {logger.info("有一连贯敞开！以后在线人数为" + getOnlineCount());
        // 从 set 中删除
        webSocketSet.remove(this);
        // 在线数减 1
        subOnlineCount();
        logger.info("有一连贯敞开！以后在线人数为" + getOnlineCount());
    }

    /**
     * 收到客户端音讯后调用的办法
     *
     * @param message 客户端发送过去的音讯
     */
    @OnMessage
    public void onMessage(String message) {logger.info("收到信息:" + message);
        System.out.println("webSocketSet Size" + webSocketSet.size());
    }

    /**
     * 发送音讯
     *
     * @param message
     */
    public void sendMessageToPad(String message) {for (WebSocketServer item : webSocketSet) {
            try {item.sendMessage(message);
            } catch (IOException e) {e.printStackTrace();
            }
        }
    }


    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {logger.error("产生谬误");
        error.printStackTrace();}

    /**
     * 实现服务器被动推送
     */
    public void sendMessage(String message) throws IOException {this.session.getBasicRemote().sendText(message);
    }

    public static synchronized int getOnlineCount() {return onlineCount;}

    public static synchronized void addOnlineCount() {WebSocketServer.onlineCount++;}

    public static synchronized void subOnlineCount() {WebSocketServer.onlineCount--;}
}

看起来都没问题，咱们把异样信息都打进去

Caused by: javax.websocket.DeploymentException: Cannot deploy POJO class [com.smec.fin.service.impl.WebSocketServer$$EnhancerBySpringCGLIB$$6b71ea8] as it is not annotated with @ServerEndpoint
    at org.apache.tomcat.websocket.server.WsServerContainer.addEndpoint(WsServerContainer.java:245)
    at org.apache.tomcat.websocket.server.WsServerContainer.addEndpoint(WsServerContainer.java:228)
    at org.springframework.web.socket.server.standard.ServerEndpointExporter.registerEndpoint(ServerEndpointExporter.java:156)
    ... 17 common frames omitted

问题起因

问题定位到 WsServerContainer.java:245 行，打上断点，咱们发现 pojo 被代理了，其实依据打印日志 com.smec.fin.service.impl.WebSocketServer$$EnhancerBySpringCGLIB$$6b71ea8 也能够看进去，应用了 CGLIB 代理，那么问题就很显著了，此类被 AOP 做了代理，在 AOP 中将此类移除就能够了。

失常的 pojo

被代理的 pojo

AOP 配置

将 WebSocketServer 类从 AOP 中移除，我的项目即可失常启动

    @AfterThrowing(pointcut = "execution( * com.smec.fin.service..*.*(..)) && !execution(* com.smec.fin.service.impl.WebSocketServer.*(..))", throwing = "e")
    public void afterThrowing(JoinPoint joinPoint, Throwable e) {logger.error("Exception in {}.{}() with cause = {}", joinPoint.getSignature().getDeclaringTypeName(),
                joinPoint.getSignature().getName(), e.getCause() != null ? e.getCause() : "NULL");
    }