int a = 999;
int b = 9999;
int random_number = (int) Math.round(a + (Math.random() * b));
System.out.println(random_number);
int a = 999;
int b = 9999;
int random_number = a+ (int)(Math.random() * ((b - a) + 1));
System.out.println(random_number);