I've been having a lot of problems connecting SQL Workbench/J to Amazon Athena through the JDBC connector. Also, the instructions seem to vary between these two help resources:
Here's the error message:
[Simba]JDBC Connection Refused: [Simba]JDBC Required Connection Key(s): AwsRegion; [Simba]JDBC Optional Connection Key(s): AwsCredentialsProviderArguments, AwsCredentialsProviderClass, BinaryColumnLength, ComplexTypeColumnLength, ConnectTimeout, MaxCatalogNameLength, MaxColumnNameLength, MaxErrorRetry, MaxSchemaNameLength, MaxTableNameLength, ProxyHost, ProxyPort, ProxyPWD, ProxyUID, S3OutputEncOption, Schema, SocketTimeout, StringColumnLength, UseAwsLogger
The documentation at #1 is deprecated, as you might gather from the different filenames in the two guides. Amazon hasn't fully cleaned up their docs, since switching from their homegrown JDBC driver to the driver they've OEMed from Simba.
You did not provide the JDBC URL you're using, so I cannot provide a specific correction, but the error message you got seems pretty clear -- you apparently didn't build your JDBC URL correctly. It's missing the mandatory AwsRegion setting.
Note the URL syntax from the PDF guide for the JDBC driver you're using --
jdbc:awsathena://AwsRegion=[Region];UID=[AccessKey];PWD=[SecretKey];S3OutputLocation=[Output];[Property1]=[Value1];[Property2]=[Value2];...