I am getting this error socket exception raised by this connection while running my application.

INFO 5231 --- [nio-8087-exec-1] org.mongodb.driver.connection: Closed connection [connectionId{localValue:2}] to 192.168.0.2:27017 because there was a socket exception raised by this connection.**

    org.springframework.data.mongodb.UncategorizedMongoDbException: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='admin', source='campbell', password=<hidden>, mechanismProperties={}}; nested exception is com.mongodb.MongoSecurityException: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='admin', source='campbell', password=<hidden>, mechanismProperties={}}
        at org.springframework.data.mongodb.core.MongoExceptionTranslator.translateExceptionIfPossible(MongoExceptionTranslator.java:138)
        at org.springframework.data.mongodb.core.MongoTemplate.potentiallyConvertRuntimeException(MongoTemplate.java:2756)
        at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:2666)
        at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2409)
        at org.springframework.data.mongodb.core.ExecutableFindOperationSupport$ExecutableFindSupport.doFind(ExecutableFindOperationSupport.java:214)

        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

    Caused by: com.mongodb.MongoSecurityException: Exception authenticating MongoCredential{mechanism=SCRAM-SHA-1, userName='admin', source='campbell', password=<hidden>, mechanismProperties={}}

    Caused by: com.mongodb.MongoCommandException: Command failed with error 18 (AuthenticationFailed): 'Authentication failed.' on server 192.168.0.2:27017. The full response is { "ok" : 0.0, "errmsg" : "Authentication failed.", "code" : 18, "codeName" : "AuthenticationFailed" }

**I have declared properties in application properties-**
spring.data.mongodb.database=dbname
spring.data.mongodb.username=admin
spring.data.mongodb.password=*******
spring.data.mongodb.port=27017
spring.data.mongodb.host=192.168.0.2

Login credentials are right still I am getting this error. Exception authenticating MongoCredential also I am getting Uncategorized Mongo Db Exception

Please help me out!

As per #46934427, setting spring.data.mongodb.authentication-database=admin would probably fix your issue.

The default database in MongoDB is test, therefore, it's likely you are attempting to authenticate against the test database. Switching to the admin database (the common place for users to be created), might fix your issue.