Java heap space

import java.util.ArrayList;

public class A {

	static ArrayList<int[]> permutations(int[] a)  {
		ArrayList<int[]> ret = new ArrayList<int[]>();
		//Consumer<int[]>ret=new Consumer<int[]>();
		permutation(a, 0, ret);
		return ret;
	}

	/*public void permutation(int[] arr, int pos, Consumer<int[]> consumer) {
	    if (arr.length - pos == 1)
	        consumer.accept(arr);
	    else
	        for (int i = pos; i < arr.length; i++) {
	            swap(arr, pos, i);
	            permutation(arr, pos + 1, list);
	            swap(arr, pos, i);
	        }
	}*/

	public static void permutation(int[] arr, int pos, ArrayList<int[]> list) {
	    if (arr.length - pos == 1)
	        list.add(arr.clone());
	    else
	        for (int i = pos; i < arr.length; i++) {
	            swap(arr, pos, i);
	            permutation(arr, pos + 1, list);
	            swap(arr, pos, i);
	        }
	}

	public static void swap(int[] arr, int pos1, int pos2) {
		int h = arr[pos1];
		arr[pos1] = arr[pos2];
		arr[pos2] = h;
	}
	public static void main(String[] args) throws java.lang.Exception {
		int[] a = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,
				30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60};
		
		ArrayList<int[]> list = permutations(a);
		for (int[] s : list) {
			for (int i : s) {
				System.out.print(i+",");
				//G1.add(i);
			}
			System.out.println();
		}
	}
	}