1、代码

package com.sm2005a;

import org.junit.jupiter.api.Test;

import java.io.File;

public class ListAllFileTests {

    public void listAllFile(String path) {
        File fileFold = new File(path);
        File[] files = fileFold.listFiles();

        for (File f : files) {
            if(f.isDirectory()) {
                // 如果是目录
                listAllFile(f.getAbsolutePath());
            }
            else {
                // 如果是文件
                System.out.println("FILE:"+f.getAbsolutePath());
                String fileName = f.getAbsolutePath();

                // 判断扩展名
                if(fileName.lastIndexOf(".") != -1 && fileName.lastIndexOf(".") != 0) {
                    String extName = fileName.substring(fileName.lastIndexOf("."));
                    if(extName.equalsIgnoreCase(".mp4")) {
                        System.out.println("Video File:"+f.getAbsolutePath());
                    }
                }
            }
        }
    }

    @Test
    public void listPath() {
        listAllFile("E:\\videos");
    }
}