当我尝试连接Mongo时，出现连接失败。我也尝试了sudo服务mongo start
C：\ Program Files \ MongoDB \ Server \ 4.0 \ bin> mongo
MongoDB shell version v4.0.9
连接到：
mongodb://127.0.0.1:27017/?gssapiServiceName=mongodb
2019-05-20T11:55:07.207+0530 E QUERY [js]
错误：
couldn't connect to server 127.0.0.1:27017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:27017 :: caused by :: No connection could be made because the target machine actively refused it. :
connect@src/mongo/shell/mongo.js:343:13
@(connect):2:6
exception: connect failed