At a guess - and that's all it can be since we have no access to your computer - it's something to do with
rather than the code you show.
If I use an online Java IDE, you code will not compile with this line in:
This is to be expected, since I don;t have the package it refers to.
Remove the line, the code runs fine and I get exactly what I expected:
How, To, Do, In, Java
So remove the line yourself, and see if it works. When it does, start looking at the package to see what's wrong with that!
Sorry, but we can't do that for you!