Java Random Class Question.?

I am trying to generate 5 random numbers using the two classes that i created. I am getting 5 numbers, but they all are zeros.
import java.util.Random;
public class Lottery
{
private int[] num = new int[5];
public int[] Lottery()
{
Random random = new Random();
for(int i = 0; i < num.length; i++){
num[i] = random.nextInt(51);
}
return num;
}
public String toString()
{
String s = "";
for(int i = 0; i < num.length; i++)
s += num[i] + "\n";
return s;
}
}
————————————–…
import java.util.Scanner;
public class Lab1
{
public static void main(String [] args)
{
Lottery lot = new Lottery();
Scanner scan = new Scanner(System.in);
System.out.println("Lottery Numbers: \n" + lot.toString());
}
}