Regular expression for not empty

Question

I need a Java regular expression, which checks that the given String is not Empty. However the expression should ingnore if the user has accidentally given whitespace in the

Answer 1

You can also use positive lookahead assertion to assert that the string has atleast one non-whitespace character:

^(?=\s*\S).*$

In Java you need

"^(?=\\s*\\S).*$"