Java第十一天（实训学习（十）Java IO流练习题）

练习：

1、利用File实现递归删除，写死。（删除从键盘输入的后缀名文件）

2、统计工作空间下Java文件，并输出代码行数

3、复制文件

package day1106;

import java.io.*;
import java.nio.file.*;

import java.nio.file.attribute.BasicFileAttributes;
import java.util.Locale;
import java.util.Scanner;

public class Demo02 {
    private static  int number;
    private static long Count = 0;

    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        do {
            System.out.println("请输入一个需要执行的序号：" + "\n" + "\t" + "1：删除文件" + "\n" + "\t" + "2：统计java文件" + "\n" + "\t" + "3：复制文件" + "\n" + "\t" + "4：退出");
            number = sc.nextInt();
            switch (number) {
                /**
                 * 退出系统
                 */
                case 4:
                    System.out.println("已退出！");
                break;

                /**
                 * 删除文件
                 */
                case 1:
                    Scanner scanner = new Scanner(System.in);
                    System.out.println("请输入要删除的文件后缀名（不用加.）：");
                    String deletef = scanner.nextLine();
                    deleteFilesdeletef(new File("G:/test/Dele/day1029"),deletef);
                    System.out.println("所有后缀名为"+deletef+"的文件删除完成");
                    //scanner.close();
                    break;

                /**
                 * 统计Java文件并输出代码行数
                 */
                case 2:
                    Path rootPath = Paths.get("G:/test");
                    Files.walkFileTree(rootPath, new SimpleFileVisitor<Path>() {
                        @Override
                        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                            if (file.toString().endsWith(".java")) {
                                Count += Files.lines(file).count();
                            }
                            return FileVisitResult.CONTINUE;
                        }
                    });

                    System.out.println("代码行数: " + Count);
                    break;

                /**
                 * 复制文件
                 */
                case 3:
                    Path sourcePath = Paths.get("G:/shixun/test/src/cn/hxzy/pro/Demo01.java"); // 源文件路径
                    Path destinationPath = Paths.get("G:/test/Dele/copytest/thistest.java"); // 目标文件路径

                    try {
                        Files.copy(sourcePath, destinationPath, StandardCopyOption.REPLACE_EXISTING);
                        System.out.println("文件复制成功！");
                    } catch (IOException e) {
                        System.out.println("文件复制失败: " + e.getMessage());
                    }

                    break;
                default:
                    System.out.println("输入无效，请重新输入一个正确的序号！");
                    break;
            }
        } while (number != 4);
    }


    /**
     * 删除
     * @param
     */
    public static void deleteFilesdeletef(File directory,String deletef) {
        File[] files = directory.listFiles();

            //File[] files = directory.listFiles((f) -> f.isFile() && f.getName().endsWith(i)); // 判断是否为.png文件

            if (files != null) {
                for (File file : files) {
                    if (file.isDirectory()) {
                        deleteFilesdeletef(file, deletef);
                    }else {
                        if (file.getName().toLowerCase(Locale.ROOT).endsWith("."+deletef)){
                            boolean deleted =file.delete();
                            if (!deleted){
                                System.out.println("删除文件失败: " + file.getAbsolutePath());
                            }
                        }

                    }
                }

            }
    }
}

练习：

通过字节输入和输出流实现将视频文件进行复制。

package day1106;


import java.io.*;

public class Demo03 {
    public static void main(String[] args) {
        /**
         * 通过字节输入和输出流实现将视频文件进行复制。
         */
        try {
            // 源视频文件路径
            String Sourcepath = "https://files.youth.cn/video/zq_video/202411/P020241107344980818272.mp4";
            // 目标视频文件路径
            String Targetpath = "G:/test/Dele/测试/day1104";

            FileInputStream fis = new FileInputStream(Sourcepath);
            FileOutputStream fos = new FileOutputStream(Targetpath);
                byte[] buffer = new byte[1048576];
                int length;
                while ((length = fis.read(buffer)) != -1) {
                    fos.write(buffer, 0, length);
                }
                fis.close();
                fos.close();
                System.out.println("视频复制成功！");
            } catch (IOException e) {
                System.out.println("发生错误：" + e.getMessage());
        }
    }
}