com.mongodb.MongoSocketOpenException: Exception opening socket
at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:67) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:126) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117) ~[mongodb-driver-core-3.8.2.jar:na]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_181]
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) ~[na:1.8.0_181]
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_181]
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_181]
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_181]
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_181]
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_181]
at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_181]
at com.mongodb.internal.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:64) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:62) ~[mongodb-driver-core-3.8.2.jar:na]
. 3 common frames omitted
Caused by: java.net.ConnectException: Connection refused: connect
查看mongodb是否打开，java那边配置的端口号和ip地址等连接信息是否正确。
防火墙是否允许连接。