averagely, how much time does a person need to become good java developer?

Answer 1

https://www.quora.com/How-much-time-does-it-take-to-master-Java-and-what-is-the-best-platform-to-learn-it-from

Answer 2

Please share this info :

http://www.openculture.com/freeonlinecourses#Computer Science Courses

https://www.ted.com/talks/shai_reshef_a_tuition_free_college_degree