you can make a sieve of eratostoles with the first 2000 numbers in Java and you can write the number and determine if it is prime or not
public class Main { public static void main(String[] args) { int n = 2000; boolean prime[] = new boolean[n+1]; for(int i=0;i<n;i++) prime[i] = true; for(int p = 2; p*p <=n; p++) { if(prime[p] == true) { for(int i = p*2; i <= n; i += p) prime[i] = false; } } for(int i = 2; i <= n; i++) { if(prime[i] == true) System.out.print(i + " "); } } }