How to get input data from keyboard?

Question

Android

Good afternoon.

I would like to receive input characters from the keyboard on android.
Suppose we enter the data now, and he writes them to the file.

I switched to mobile development only recently, I'm still learning.
There is no basic understanding of how to work with hardware and things like a keyboard.
If it's not difficult, give an example, and what you need to read.

Thanks in advance gentlemen

PS: any keyboard at adb level
PSS: Play Market will not release
PSSS: required for business

Answer 1

Write your own keyboard. Persuade the user to set it as the default input method. Write in a special section about the data collected by the application that you collect all the input data. If moderation misses this, I will be very surprised.