Show only decimal digits in Java if it is a real decimal digit

Sometimes a double can have an integer value and sometimes it can be a "real decimal digit".

I am searching for a way to print only the decimal digit if it has not a integer value:

public static void main(String[] args) {

    double test = 1; // should print "1"
    double test2 = 1.5; // should print "1,5"

    System.out.println(String.format("%.1f", test));  // OUTPUT: "1,0"
    System.out.println(String.format("%.1f", test2)); // OUTPUT: "1,5"
}

Thanks for your help guys!

Regards