使用File类的list方法遍历指定目录下的所有目录

完整代码

import java.io.*;class Main {public static void main(String[] args) {File dir = new File("D:");File[] files = dir.listFiles();FileFilter fileFilter = new FileFilter() {public boolean accept(File file) {return file.isDirectory();}};files = dir.listFiles(fileFilter);System.out.println(files.length);if (files.length == 0) {System.out.println("目录不存在或它不是一个目录");}else {for (int i=0; i< files.length; i++) {File filename = files[i];System.out.println(filename.toString());}}}
}

结果输出

8
D:\sumbile text
D:\idea
D:\movie
D:\test.txt
D:\wechart
D:\music
D:\software
D:\workspace

只获取输出指定目录下的文件夹

完整代码

public class Main {    public static void main(String[] args) throws Exception {        File file = new File("//Users//zhangshuhang//Desktop");        getAllDirectory(file);    
}    
public static void getAllDirectory(File file) {//创建过滤器        File[] f = file.listFiles(new GetAllDirectory());        for (File f1 : f) {            System.out.println(f1);//判断目录是否为空            if (f1.length() != 0)                getAllDirectory(f1);        }    }
}class GetAllDirectory implements FileFilter {public boolean accept(File pathname) {// 去除所有非文件夹if (pathname.isDirectory()) {return true;}return false;}
}