Is there jave ee contract implementation?

Question

Like on jdbc java provide an interfaces, I see the interfaces like a contract for implementers (Drivers from multiple vendor) to implement those interfaces with respect to their documented functionality from java.

But on java ee, and based on this answer : https://stackoverflow.com/posts/7571260/revisions

It's the same case on jave ee, the application servers are vendors and they implement jave ee abstract API, but on jdbc (And I mentioned it just as an example) the interfaces on java.sql package define the contract, but on jave ee(for example HttpServlet class) where is the interface the defines the general rules from java to this class that application server have to implement? or is there any external agreements among application servers to implement the functionality of java ee classes? Or java ee doc (like on https://docs.oracle.com/javaee/7/api/ ) is adopted as an agreement?

Some people will see my question is useless, but I want to know the root of any stuff I want to learn, and my mind is used to answer small deal questions.

Answer 1

There are test suites that the vendor implementations are tested against, which obviously need to pass. The specifications also need to be obeyed to be a valid Java EE implementation. The Javadoc API is not the spec, but rather a side effect of it.