Java模拟Dos下的tree命令

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Arrays;

public class ThreadTest
{

 /**
  * @param args
  * @throws IOException
  */
 
 public static void main(String[] args) throws IOException
 {
  
  Scanner in = new Scanner(System.in);
  System.out.println("Please input a Path to list the files:");
  String strPath = in.next();
  File file = new File(strPath);

  FileWriter fileWriter= new FileWriter("D:" + File.separator + "FileList.txt");
  try
  {

　fileWriter.write(strPath + "\r\n");
   ListFiles(fileWriter, file, false);
  } catch (Exception e)
  {
   e.printStackTrace();
  }
  finally
  {
   fileWriter.close();
  }
 }
 

 // level 为 前面所有层级文件是否需要输出 "│"
 public static void ListFiles(FileWriter fileWriter, File aFile, boolean...level) throws IOException
 {
  if (!aFile.exists()) return;
  
  File[] files = aFile.listFiles();
  
  if (files == null)
   return;
  
  for (int i = 0; i < files.length; i++)
  {
   for (boolean l : level)
   {
    if (l)
     fileWriter.write("│");
    else
     fileWriter.write("  ");
    
   } //for (boolean l : level)
   
   if (i == files.length - 1)
    fileWriter.write("└" + files[i].getName() + "\r\n");
   else
    fileWriter.write("├" + files[i].getName() + "\r\n");
   

   // 如果是文件夹，递归
   if (files[i].isDirectory())
   {
    boolean[] lv = Arrays.copyOf(level, level.length+1);
    lv[level.length] = (i != files.length - 1);
    ListFiles(fileWriter, files[i], lv);;
   } //if (files[i].isDirectory())
   
  } //for (int i = 0; i < files.length; i++)

 } //public static void ListFiles...
 
}