vampire numbers

public class Vampire {	static int f1;	static int f2;	public static boolean isVampire4Dig(int n) {		String s = Integer.toString(n);		String t, t2;		char[] digits = s.toCharArray();		int[][] perm = {{0,1,2,3},{0,1,3,2},{0,2,1,3},{0,2,3,1},			{0,3,1,2},{0,3,2,1},{1,0,2,3},{1,0,3,2},{1,2,3,0},			{1,3,2,0},{2,0,3,1},{2,1,3,0}};		for(int[] p : perm) {			if(!(digits[p[1]] == '0' && digits[p[3]] == '0')) {				t = new String(digits, p[0], 1) + 					new String(digits, p[1],1);				t2 = new String(digits, p[2], 1) + 					new String(digits, p[3],1);				f1 = Integer.parseInt(t);				f2 = Integer.parseInt(t2);				if(f1 * f2 == n)					return true;			}		}		return false;	}	public static void main(String[] args) {		for(int i=1000;i<=9999;i++)			if(isVampire4Dig(i))				System.out.println(i + " is a vampire number. "					+ "Fangs: " + f1 + ", " + f2);	}}