package com.itranswarp.learnjava;import java.io.File;import java.io.IOException;/** * Learn Java from https://www.liaoxuefeng.com/ *  * @author liaoxuefeng */public class Main {   public static void main(String[] args) throws IOException {      File currentDir = new File(".");      listDir(currentDir.getCanonicalFile(),0);   }   static void listDir(File dir,int number) throws IOException {      // TODO: 递归打印所有文件和子文件夹的内容      File[] fs = dir.listFiles();      int num=number;      if (fs != null) {         for (File f : fs) {            if(f.isDirectory()){               System.out.println(space(num)+f.getName()+"/");               File fin=new File(f.getAbsolutePath());               listDir(fin,num+1);            }            else if(f.isFile()){               System.out.println(space(num)+f.getName());            }         }      }   }   static String space(int number){   StringBuilder s=new StringBuilder();   for (int i =0;i<number;i++){      s.append("\t");   }   return s.toString();   }}