java 复制文件夹下所有文件夹和文件

可以使用递归的方式来实现文件夹下所有文件和文件夹的复制。

以下是一个简单的 Java 代码示例：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyFolder {
    public static void main(String[] args) {
        String sourceFolder = "source_folder_path";
        String destinationFolder = "destination_folder_path";
        File source = new File(sourceFolder);
        File destination = new File(destinationFolder);
        try {
            copyFolder(source, destination);
            System.out.println("Folder copied successfully.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void copyFolder(File source, File destination) throws IOException {
        if (source.isDirectory()) {
            if (!destination.exists()) {
                destination.mkdir();
            }
            String[] files = source.list();
            for (String file : files) {
                File srcFile = new File(source, file);
                File destFile = new File(destination, file);
                copyFolder(srcFile, destFile);
            }
        } else {
            FileInputStream inputStream = new FileInputStream(source);
            FileOutputStream outputStream = new FileOutputStream(destination);
            byte[] buffer = new byte[1024];
            int length;
            while ((length = inputStream.read(buffer)) > 0) {
                outputStream.write(buffer, 0, length);
            }
            inputStream.close();
            outputStream.close();
        }
    }
}

以上代码会将 `source_folder_path` 文件夹下的所有文件和文件夹复制到 `destination_folder_path` 文件夹下。如果目标文件夹不存在，代码中会自动创建。