diff --git a/src/main/java/com/zhangshu/chat/demo/websocket/ChatRoom.java b/src/main/java/com/zhangshu/chat/demo/websocket/ChatRoom.java
index 8af3324..be45400 100644
--- a/src/main/java/com/zhangshu/chat/demo/websocket/ChatRoom.java
+++ b/src/main/java/com/zhangshu/chat/demo/websocket/ChatRoom.java
@@ -82,6 +82,7 @@ public class ChatRoom {
                 .map(RoomUserVo::getId)
                 .map(userSessionCache::get)
                 .map(sessionCache::get)
+                .filter(Objects::nonNull)
                 .forEach(v -> {
                     this.sendMessage(text, v);
                 });
@@ -96,6 +97,9 @@ public class ChatRoom {
      */
 
     private void sendMessage(String message, Session session) {
+        if (!session.isOpen()) {
+            return;
+        }
         try {
             session.getBasicRemote().sendText(message);
         } catch (IOException e) {