监考接口修改

themis-exam/src/main/java/com/qmth/themis/exam/websocket/WebSocketOeServer.java

@@ -186,7 +186,7 @@ public class WebSocketOeServer implements Concurrently {
     public void onMessage(String message, Session session) {
         //可以群发消息
         //消息保存到数据库、redis
-        if (Objects.nonNull(message)) {
+        if (Objects.nonNull(message) && session.isOpen()) {
             try {
                 //解析发送的报文
                 JSONObject jsonObject = JSONObject.parseObject(message);