What to read on reading text files?

Question

Java

What to read on reading text files? so that the desired file opens in a frame as in the screenshot below.



And also about reading various text formats, such as fb2, pdf, and so on. etc.

Answer 1

Read text files!

Answer 2

Reading a text file has nothing to do with displaying in any frame. You are reading a file into a variable. And in the frame you already display the contents of the variable. The frame doesn't care where the data in the variable comes from, just like the file parser doesn't care where the data will be displayed.
For all sorts of fb2 and other things, you need to read the format specifications. I am sure that you can find ready-made libraries for parsing these formats.