> It's certainly not fair use, it was specifically to build a competing product/commercial ecosystem to Oracle's The commercial nature of the work is just one

> It's certainly not fair use, it was specifically to build a competing product/commercial ecosystem to Oracle's The commercial nature of the work is just one factor determining fair use. Another is "the amount and substantiality of the portion used in relation to the copyrighted work as a whole". And the API structure is a quite small part of the JDK as a whole, and has a different nature than implementation code as well.