What do you need to know from the java world in order to roll into android?

Question

Java

Actually, I just read the first part of Schildt's book (complete guide, 9th edition).
It includes, except for the history and a brief overview of java:

• Basic programming knowledge in general (variables, types, operations, loops, etc.)
  
• Inheritance
  
• Packages and Interfaces
  
• Exceptions
  
• Multithreading
  
• Enum, autoboxing, annotations
  
• Streaming I/O, Reading and Writing to Files
  
• Generalizations
  
• Lambda
  

After the exceptions, it seems to me, they gave not very detailed information (although it is clear, the book is 1377 pages long, and only 500 have been read).
I know exactly what else I will read about the collections. Is knowledge of jdbc required (not completely sure about it, because it seems that androit natively uses something else)?
What am I missing, in order to be especially problem-free (at least by googling once an hour, but no more: D) to roll into java with such knowledge?

Answer 1

1. HelloWorld in Java, displaying text on the screen
   Source: I want to code for Android. Question #2

Answer 2

in fact, knowledge of the syntax and this should be enough to start, of course you have to learn deeper, but it’s enough to start
https://habrahabr.ru/post/132241/
https://habrahabr.ru/post/132374/