我有一个通过WebSocket连接到角度客户端的spring boot REST API后端。我设法通过角度连接到websocket，但是订阅不起作用。服务器没有发回我的消息，而我订阅了正确的频道。单击Angular页面中的按钮时，将调用Angular上的“ sendMessage（）”。
这是我得到的结果：
next(b for a, b in zip(list_a, list_b) if a != b)
我的Spring Boot代码：
Angular is running in the development mode. Call enableProdMode() to enable the production mode.
stomp.umd.js:728 Opening Web Socket...
client:52 [WDS] Live Reloading enabled.
stomp.umd.js:728 Web Socket Opened...
stomp.umd.js:728 >>> CONNECT
accept-version:1.0,1.1,1.2
heart-beat:10000,10000
stomp.umd.js:728 Received data
stomp.umd.js:728 <<< CONNECTED
heart-beat:0,0
version:1.2
content-length:0
stomp.umd.js:728 connected to server undefined
stomp.umd.js:728 >>> SUBSCRIBE
id:sub-0
destination:/topic/chat
stomp.umd.js:728 >>> SEND
destination:/app/send
content-length:9