Java-螺旋方阵

public void screwMatrix() {
System.out.print("请输入数字：");
Scanner input = new Scanner(System.in);
int number = input.nextInt();

int[][] matrix = new int[number][number];
int max = number * number;
int row = 0, col = 0;
int direction = 0;
for (int j = 1; j <= max; j++) {
matrix[row][col] = j;
switch (direction) {
case 0 :
if (col + 1 >= number || matrix[row][col + 1] > 0) {
direction += 1;
direction %= 4;
row += 1;
} else {
col = col + 1;
}
break;
case 1 :
if (row + 1 >= number || matrix[row + 1][col] > 0) {
direction += 1;
direction %= 4;
col -= 1;
} else {
row = row + 1;
}
break;
case 2 :
if (col - 1 < 0 || matrix[row][col - 1] > 0) {
direction += 1;
direction %= 4;
row = row - 1;
} else {
col = col - 1;
}
break;
case 3 :
if (row - 1 < 0 || matrix[row - 1][col] > 0) {
direction += 1;
direction %= 4;
col += 1;
} else {
row = row - 1;
}
break;
default :
System.out.println("ERROR");
System.exit(0);
}
}
for (int j = 0; j < number; j++) {
for (int k = 0; k < number; k++) {
// 判断输出最大数的长度
int size = ((number * number) + "").length();

for (int i = 0; i <= (size - (matrix[j][k] + "").length() + 1); i++) {
System.out.print(" ");
}
System.out.print(matrix[j][k]);
}
System.out.println("");
}
}