Untitled

package pattern;

class fullbutterfly{
    public static void main(String[] args) {
        int n = 4;
        int spaces = (2 * n) - 2;
        int stars = 1;
        int currentline = 1;
        while (currentline <= n) {
            // print stars
            for (int i = 1; i <= stars; i++) {
                System.out.print("* ");
            }
            //print spaces
            for (int i = 1; i <= spaces; i++) {
                System.out.print("  ");
            }
            //print stars
            for (int i = 1; i <= stars; i++) {
                System.out.print("* ");
            }
            // prepare for next line
            System.out.println();
            if (currentline<n)
            {
                stars++;
                spaces = spaces - 2;
            }
            else {
                stars--;
                spaces = spaces+1;
            }
            currentline++;
        }
    }
}