Oracle has no formal program or tooling that can effectively audit a customer’s use of Java to determine a subscription requirement.
What Oracle is doing, according to Specifics About Java Usage Metrics, is collecting installation data via Java’s auto-updater that is running throughout your organization. Think spyware. Oracle sales people take this data, do a bit of research on your company, and reach out in an escalating approach that ends up feeling like an audit.
There is no difference between this sales-centric racket and a formal audit if the result is being duped into over-purchasing. Oracle’s standard path to enforcing intellectual property is its audit organization and the subsequent nomination to Oracle Legal where necessary to dislodge a stubborn customer. For Java, subscriptions are secured through attrition.
This is not to say you shouldn’t subscribe for Java given the licensing rules were announced mid-2018. How much, though, is difficult to answer. Remend’s approach is to derive good faith estimates based on the Java requirements of broadly-deployed applications. If only to maximize revenue, Oracle’s pursuit is corporate-wide multi-year subscriptions that enforce volume-inducing policies such as its view of VMware.