How to establish a connection to secret server using RuleName and Onboarding key

[acs-developer]

Any way to do this in Java? I was able to do this using command line SDK took, but couldn't find a way to do this using REST API in Java.

What I'm trying to do is to avoid saving application account credentials like these in Java code or configuration:

secret_server.oauth2.username = app_user
secret_server.oauth2.password = app_user_password

SDK CLI tool uses Rule Name and Onboarding key to initialize and then establish a connection with the secret server. 3 config files are created on the server, which will be used to retrieve secrets in subsequent calls. Anything similar available in Java, or REST API?