package com.itranswarp.learnjava;import java.io.File;import java.io.IOException;/** * Learn Java from https://www.liaoxuefeng.com/ * * @author liaoxuefeng */public class Main {    static int count = 0;    public static void main(String[] args) throws IOException {//        File currentDir = new File("C:\\AAAA");        File currentDir = new File(".");        File canonicalFile = currentDir.getCanonicalFile();        System.out.println(canonicalFile);        listDir(currentDir.getCanonicalFile());    }    static void listDir(File dir) throws IOException {        // TODO: 递归打印所有文件和子文件夹的内容        File[] fs = dir.listFiles();        if (fs != null) {            for (int i = 0; i < fs.length; i++) {                //打印第一条文件或目录                File f = fs[i];                if (count > 0 && f.isFile() && i > 0) {                    for (int j = 0; j < count; j++) {                        System.out.print("  ");                    }                }                System.out.println(f.getName());                //目录                if (f.isDirectory()) {                    count++;                    if ((f.list().length > 0)) {                        for (int j = 0; j < count; j++) {                            System.out.print("  ");                        }                    }                    listDir(f);                    count--;                }            }        }    }}

展示bug还没有解决么

package com.itranswarp.learnjava;

import java.io.File;
import java.io.IOException;

/**
* Learn Java from https://www.liaoxuefeng.com/
*
* @author liaoxuefeng
*/
public class Main {

static int count = 0;

public static void main(String[] args) throws IOException {
// File currentDir = new File("C:\\AAAA");
File currentDir = new File(".");
File canonicalFile = currentDir.getCanonicalFile();
System.out.println(canonicalFile);
listDir(currentDir.getCanonicalFile());
}

static void listDir(File dir) throws IOException {
// TODO: 递归打印所有文件和子文件夹的内容
File[] fs = dir.listFiles();

if (fs != null) {
for (int i = 0; i < fs.length; i++) {

//打印第一条文件或目录
File f = fs[i];

if (count > 0 && f.isFile() && i > 0) {
for (int j = 0; j < count; j++) {
System.out.print(" ");
}
}
System.out.println(f.getName());

//目录
if (f.isDirectory()) {
count++;
if ((f.list().length > 0)) {
for (int j = 0; j < count; j++) {
System.out.print(" ");
}
}
listDir(f);
count--;
}

}
}
}

}