JAVA Two-Dimensional Array

static final int ROW = 4;
static final int COL = 3;

public static void main(String[] args) {
    String[][] parkingSpace = new String[ROW][COL];

    System.out.println(" \t1\t2\t3");
    String fill = "□";

    for(int i=0; i<=parkingSpace[ROW].length + 1; i++) {
        System.out.print(i);
        for(int j=0; j<=parkingSpace[COL].length + 1; j++) {
            if(parkingSpace[i][j] != null) {
                fill = "■";
                System.out.print('\t' + fill);
            } } else {
                System.out.print('\t' + fill);
            }
            }
        System.out.println();
        }

    1     2     3
1   □    □    □
2   □    □    ■
3   □    □    □
4   □    □    □