Java print pascal triangle

/**
 * @author lautturi.com 
 * Java example: java pascal triangle
 */

import java.util.*;

public class Lautturi {
	public static boolean isPalindrome(int x) {
		String str = Integer.toString(x);
		String reverse = new StringBuilder(str).reverse().toString();
		return str.equals(reverse);
	}

	public static void main(String[] args) {
		int numRows = 10;
		List<Integer> preList = new ArrayList<Integer>();
		List<Integer> curList=null;
		for (int i = 0; i < numRows; i++) {
			curList = new ArrayList<Integer>();
			
			for (int j = 0; j <= i; j++) {
				Integer val = 0;
				if(j==0 || j==i) {
					val = 1;
				}else {
					val = preList.get(j-1)+preList.get(j);
				}
				curList.add(val);
				System.out.print(val+" ");
			}
			System.out.println();
			preList=curList;
		}
	}
}

output:

1 
1 1 
1 2 1 
1 3 3 1 
1 4 6 4 1 
1 5 10 10 5 1 
1 6 15 20 15 6 1 
1 7 21 35 35 21 7 1 
1 8 28 56 70 56 28 8 1 
1 9 36 84 126 126 84 36 9 1