StringBuilder append() and null values

Question

I have a list of Strings, and I want to concatenate them with spaces in between. So I\'m using StringBuilder. Now if any of the Strings ar

Answer 1

I'm not sure why you'd expect it to come out empty, given that the documentation is pretty clear:

If str is null, then the four characters "null" are appended.

Basically you need to either not call append at all if you have a null reference, or switch the value for "".

You could write a method to do this substitution if you find yourself doing it a lot:

public static String nullToEmpty(String text) {
    return text == null ? "" : text;
}

Indeed, I've just looked at the Guava documentation and the Strings class has exactly that method (but with a parameter called string instead of text).