A great summary (pdf file) of the basics of the Java language is available at an excellent price !!! .
I would highly recommend this very helpful summary to anyone who wants to learn Java Because
I have created this summary based on my personal experience programming in Java language Which enabled me to enter the field of developing Android applications.
This summary is available on the following lessons:
-ٍVarriable data type.
-Some important things about coding with java.
-How to make Comments.
-most important method and function.
-Whil loop/for loop/ do whil loop.
-Array / two dimensional array.
-Getter and setter.
-Example of polymorphism.
Good luck (: !!