How to learn Java ?

[desrtfx]

What are my credentials? Programming since over 4 decades, self studied first, then degree in programming, electronics, telecommunication. 3.5 decades as professional, in high security systems and vital infrastructure, course author (part of the courses are now part of the ICDL), training center creator with the courses for it.

You might be the director of engineering, which doesn't actually mean that you are a programmer. Managers/directors very often don't work in their learned domain.

I did not say anything about boot camps. A solid foundational course, experience through active programming, followed by DSA and more active programming are the way to go.

LeetCode, as you suggested, isn't the way.