IDEA. Solution to find and remove empty lines in a file?

Question

Programming

The refactoring results in a bunch of empty lines that autoformatting doesn't remove. Scrolling and deleting manually in the code for a couple of thousand lines is not an option.
Is there any solution other than writing your own plugin?
PS: found some solution for anyone interested:

replace \n\n by \n (STRG-R with regex)

But still interested in automating this process