public class Main {

    public static void main(String[] args) {

        printSquareStar(5);

        /* output is:

            *****

            ** **

            * * *

            ** **

            *****

        */

    }

    public static void printSquareStar (int number) {

        if (number < 5) {

            System.out.println("Invalid Value");

        } else {

            for (int row = 1; row <= number; row++) {

                for (int column = 1; column <= number; column++) {

                    if (row == 1 || row == number || column == 1 || column == number || row == column || column == (number - row + 1)) {

                        System.out.print("*");

                    } else {

                        System.out.print(" ");

                    }

                }

                System.out.println();

            }

        }

    }

}