swing syntax highlighter

I need some advice on creating a syntax highligher for java application using swing. The application should allow to edit a file and highlight syntax.

I don't know the swing library, what should I look for?

How do you add syntax highlights?

To add a syntax highlighting language, simply check its checkbox in the main list of languages. It will appear with a checkmark in bold font to show that it has been selected but not yet installed.

What is syntax highlighting in Java?

Syntax highlighting determines the color and style of source code displayed in the Visual Studio Code editor. It is responsible for colorizing keywords like if or for in JavaScript differently than strings and comments and variable names.

I use RSyntaxTextArea and it works well.