title: Switching two lines in a text file in Java
body: <p>I've been stuck on this for a while and I've finally decided to plead for help.
  So I have a small text file and the user wants to switch 2 lines from it, the user enters the indexes of the 2 lines and I have to switch em.
  So far my ideas have been to either use replaceALL with 2 regexes
  , but A: That probably won't switch them but just end up replacing one with the other, leaving me with a duplicate and B: I have no idea how to locate the nth line using regex;
  or use - Files.readAllLines(Paths.get(name)).get(index); to get the two lines but then I'm still struggling with the actual switching process.</p>