spring boot项目启动连接mongodb报错。

2021-06-09 17:10:34,663 INFO  org.mongodb.driver.cluster - Exception in monitor thread while connecting to server node1:27017
com.mongodb.MongoSocketException: node1
	at com.mongodb.ServerAddress.getSocketAddresses(ServerAddress.java:211)
	at com.mongodb.internal.connection.SocketStream.initializeSocket(SocketStream.java:75)
	at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:65)
	at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:128)
	at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.UnknownHostException: node1
	at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
	at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
	at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
	at java.net.InetAddress.getAllByName0(InetAddress.java:1276)
	at java.net.InetAddress.getAllByName(InetAddress.java:1192)
	at java.net.InetAddress.getAllByName(InetAddress.java:1126)
	at com.mongodb.ServerAddress.getSocketAddresses(ServerAddress.java:203)
	... 5 common frames omitted

 因为是新接手项目，mongo库属于其他项目，这里只是测试应用。所以第一怀疑是项目版本驱动和mongodb库不兼容，经过替换了其他版本的mongodb库，果然可以了。

详解

查看项目中应用的是

<dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-mongodb</artifactId>
        <version>2.1.3.RELEASE</version>
    </dependency>

因为spring mongodb驱动也是封装的mongodb的官方驱动，进入spring-data-mongodb项目可以看到其中的mongodb官方驱动版本为3.8.2

再进入mongodb官方网站查看，3.8版本的最大支持4.0版本的数据库。我开始测试用连接的是4.2版本的库。（官方网站https://docs.mongodb.com/drivers/java/）

至此就这样了。