Как удалить пустую строку java

import java.util.Arrays;
import java.util.stream.Collectors;

public class App {
    public static void main(String[] args)  {
        String str = "This is a string\n \nwith empty lines";
        System.out.println(str);
        // => This is a string
        // =>
        // => with empty lines

        // способ 1
        String newStr = str.replaceAll("(?m)^\\s*$[\r\n]+", "");
        System.out.println(newStr);
        // => This is a string
        // => with empty lines

        // способ 2
        newStr = Arrays.stream(str.split("\n"))
                    .filter(x -> x.trim().length() != 0)
                .collect(Collectors.joining("\n"));
        System.out.println(newStr);
        // => This is a string
        // => with empty lines
    }   
}