螺旋矩阵问题求解

输入一个矩阵的行列数量，生成一个螺旋矩阵，比如输入5，则打印：
1 2 3 4 5
12 13 14 15 6
11 10 9 8 7
输入3，则打印：
1 2 3
8 9 4
7 6 5

下面就是他的算法

package com.huawei2;

import java.util.Scanner;

public class Test {
	private static int length;
	private Test(){
		  Scanner sc=new Scanner(System.in);
	       System.out.println("请输入一个正整数：");
	       length=sc.nextInt();
	       array =new int[length][length];
	       System.out.println(length);
	       value=1;
	}
	private static int value=0;
	 private static int[][] array=null;
	private static Direction lastDirection=Direction.Right;
	
	static enum Direction{
		Right,Down,Left,Up;
	}
	public static void initArray(){
		int row = 0,line=0;
		
		for(int i=0;i<length*length;i++)
		{
			array[row][line]=value;
			lastDirection=lastDirection(row,line);
			switch(lastDirection)
			{
				case Right:
				{
					line++;
					break;
				}
				case Down:
				{
					row++;
					break;
				}
				case Left:
				{
					line--;
					break;
				}
				case Up:
				{
					row--;
					break;
				}
			}
			value+=1;
		}
	}
	public static Direction lastDirection(int row,int line)
	{
		Direction direction=lastDirection;
		switch(direction){
			case Right:
			{
				if(line==length-1||array[row][line+1]!=0)
					direction=direction.Down;
					break;
			}
			case Down:
			{
				if(row==length-1||array[row+1][line]!=0)
				{
					direction=direction.Left;
					
				}
				break;
			}
			case Left:
			{
				if(line==0||array[row][line-1]!=0)
				{
					direction=direction.Up;
				
				}
				break;
			}
			case Up:
			{
				if(array[row-1][line]!=0)
				{
					direction=direction.Right;
				}
				break;
			}
							
		}
		return direction;
	}
	public static void main(String[] args) {
		Test test=new Test();
		test.initArray();
		// show
		for(int i1 = 0; i1 < length; i1++)
		{
			for(int j1 = 0; j1 < length; j1++)
			{
				//打印数字前加空格，使整体对齐
				if(10 > array[i1][j1])
					System.out.print("  " + array[i1][j1] + " ");
				else if(100 > array[i1][j1])
					System.out.print(" " + array[i1][j1] + " ");
				else
					System.out.print(array[i1][j1] + " ");
				
				//进行换行
				if(length- 1 == j1)
					System.out.println();
			}
		}

	}

}