错误日志：
1 events.js:167 2 throw er; // Unhandled 'error' event 3 ^ 4 5 Error: listen EADDRINUSE 127.0.0.1:9999 6 at Server.setupListenHandle [as _listen2] (net.js:1330:14) 7 at listenInCluster (net.js:1378:12) 8 at GetAddrInfoReqWrap.doListen [as callback] (net.js:1491:7) 9 at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:55:10) 10 Emitted 'error' event at: 11 at emitErrorNT (net.js:1357:8) 12 at process._tickCallback (internal/process/next_tick.js:63:19)
EADDRINUSE： 给定的地址已经被使用
端口被占用
解决办法：
查询80xx端口
netstat -nao | findstr “9999”
TCP 127.0.0.1:9999 0.0.0.0:0 LISTENING 3017
杀死进程
tskill “3017”
https://www.cnblogs.com/honeywei/articles/7920629.html
https://blog.csdn.net/qq_38967608/article/details/81188460