com.mongodb.MongoSecurityException: Exception authenticating MongoCredential{mechanism=null, userName='content_rw', source='contenttest', password=, mechanismProperties={}}
at com.mongodb.connection.SaslAuthenticator.wrapInMongoSecurityException(SaslAuthenticator.java:157) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator.access$200(SaslAuthenticator.java:37) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:66) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:44) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator.doAsSubject(SaslAuthenticator.java:162) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator.authenticate(SaslAuthenticator.java:44) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.DefaultAuthenticator.authenticate(DefaultAuthenticator.java:32) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.InternalStreamConnectionInitializer.authenticateAll(InternalStreamConnectionInitializer.java:109) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.InternalStreamConnectionInitializer.initialize(InternalStreamConnectionInitializer.java:46) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.InternalStreamConnection.open(InternalStreamConnection.java:116) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:113) ~[mongodb-driver-core-3.4.3.jar!/:na]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_151]
Caused by: com.mongodb.MongoCommandException: Command failed with error 18: 'Authentication failed.' on server a.mongo.db:27017. The full response is { "ok" : 0.0, "code" : 18, "errmsg" : "Authentication failed." }
at com.mongodb.connection.CommandHelper.createCommandFailureException(CommandHelper.java:170) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.CommandHelper.receiveCommandResult(CommandHelper.java:123) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.CommandHelper.executeCommand(CommandHelper.java:32) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator.sendSaslStart(SaslAuthenticator.java:117) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator.access$000(SaslAuthenticator.java:37) ~[mongodb-driver-core-3.4.3.jar!/:na]
at com.mongodb.connection.SaslAuthenticator$1.run(SaslAuthenticator.java:50) ~[mongodb-driver-core-3.4.3.jar!/:na]
... 9 common frames omitted
在上面这段代码卡了很久，这是部署tomcat时遇到的问题，其实就是因为MongoDB中的默认数据库是test，因此，您可能正在尝试对测试数据库进行身份验证。可以使用admin数据库进行认证。
将url加上authSource=admin,也就是下面这句就成功了。
mongodb://user:passwod@localhost/test?authSource=admin
