Practice for learning Java?

Question

Java

This question was repeatedly asked, while researching it, I made obvious conclusions:
1. Practice and again practice 2. Courses at the company.
But where to find the same practice? (I did a couple of tasks according to the source code with a description ala https://metanit.com/sharp/tutorial/3.29.php , then I redid it differently).
The question is, can someone share similar resources as I indicated above (not necessarily ru) or a trodden success story (again, practice is of interest, you can not only about it ^ ).
In any case, I will be really grateful to those who will respond and stumble across and not flip through spitting!
PS Interested in both the core (because it is currently on it), and not only.

Answer 1

1. Simple Android application. You'll have to look into the Android SDK.
2. Simple Spring application. Will have to learn Spring.
The solution of such practical problems develops in several directions at once, in contrast to the simple memorization of syntactic constructions and the solution of simple problems with their application.

Answer 2

Practice means creating your own application, and not solving some problems in a vacuum. This mb is also useful, especially at social services, but after social security you do real work, and not solve problems. So come up with a task close to the real world and solve it, along the way you will learn something to solve it.
Here, for example, for the web:
What can be pulled into one in Java?

Answer 3

open sources.
If you port some of the features from scipy to Commons.math it won't be bad.
Or write a sane interface to HDF5.

Answer 4

Hello!
Have you tried - codingbat.com/java ?