Remove all empty lines

Question

I thought that wasn\'t that hard to do, but I want to remove all empty lines (or lines just containing blanks and tabs in Java) with String.replaceAll.

My regex look

Answer 1

I'm not a day-to-day Java programmer, so I'm surprised there isn't a simpler way to do this in the JDK than a regex.

Anyway,

s = s.replaceAll("\n+", "\n");

would be a bit simpler.

Update:

Sorry I missed that you wanted to also remove spaces and tabs.

s = s.replaceAll("\n[ \t]*\n", "\n");

Would work if you have consistent newlines. If not, you may want to consider making them consistent. E.g.:

s = s.replaceAll("[\n\r]+", "\n");
s = s.replaceAll("\n[ \t]*\n", "\n");