java实现将文件从一个文件夹复制到另一个文件夹

题目: 将test目录下的所有文件及文件夹复制到study目录，除去jpg格式的图片。

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;

public class CopyFiles {
    public static void main(String[] args) {
        String sourceDirectory = "test";
        String destinationDirectory = "study";

        try {
            copyFiles(sourceDirectory, destinationDirectory);
            System.out.println("Files copied successfully!");
        } catch (IOException e) {
            System.out.println("An error occurred while copying files: " + e.getMessage());
        }
    }

    private static void copyFiles(String sourceDirectory, String destinationDirectory) throws IOException {
        File sourceDir = new File(sourceDirectory);
        File[] files = sourceDir.listFiles();

        if (files != null) {
            for (File file : files) {
                if (file.isFile()) {
                    // 获取文件扩展名
                    String extension = getFileExtension(file.getName());

                    // 如果文件不是jpg格式的图片，则进行复制
                    if (!"jpg".equalsIgnoreCase(extension)) {
                        File destination = new File(destinationDirectory + File.separator + file.getName());
                        Files.copy(file.toPath(), destination.toPath(), StandardCopyOption.REPLACE_EXISTING);
                    }
                } else if (file.isDirectory()) {
                    // 递归复制子文件夹
                    String newSourceDirectory = sourceDirectory + File.separator + file.getName();
                    String newDestinationDirectory = destinationDirectory + File.separator + file.getName();
                    copyFiles(newSourceDirectory, newDestinationDirectory);
                }
            }
        }
    }

    private static String getFileExtension(String fileName) {
        int dotIndex = fileName.lastIndexOf(".");
        if (dotIndex > 0 && dotIndex < fileName.length() - 1) {
            return fileName.substring(dotIndex + 1);
        }
        return "";
    }
}