Question

how to learn java by ourself

Answer 1

This is a good place to start:

http://www.greenteapress.com/thinkapjava/

Also, the Stanford "Introduction to Computer Science | Programming Methodology " is done with Java.
http://see.stanford.edu/see/courseinfo.aspx?coll=824a47e1-135f-4508-a5aa-866adcae1111

Answer 2

http://thenewboston.org/tutorials.php

Answer 3

@kmd285 Yah, Bucky's tutorials are very good for seeing an individual thing, but he does not really do the computer science concepts. I always suggest a real computer science class for the technical aspects. That way you develop less bad habits. Together, lecture for the science and tutorial for the small bits, they work well.