java - 复制给定 url 的文件

Question

我有包含图像文件网址的文本文件。

我想从其他目录复制这些文件。

此代码不起作用

    File source =//
    File target = //
    File urls = //
     Scanner scanner = new Scanner(urls);
    for (File child :source.listFiles())
     {
         if (child.isDirectory()) 

            while (scanner.hasNextLine()) {

            String line = scanner.nextLine();

            for (File childOfchild:child.listFiles())
             {
                 if (childOfchild.getAbsolutePath().contains(line))

                               FileUtils.copyFileToDirectory(childOfchild,target);

             }

            }
    }

问题是什么？

第一个文件包含我要复制的图像的网址

    \actor\0211_2233188435.jpg
    \actor\0405_52447453.jpg

源位置包含 704 个子目录和 250000 个文件 例如

    /media/B68E392F8E38E98F/Flickr1/Flickr/actor/0001_2124494179.jpg

Answer 1

使用递归，网上可以找到例子。 This is one of them:

public void copyDirectory(File sourceLocation , File targetLocation) throws IOException {
    if (sourceLocation.isDirectory()) {
        if (!targetLocation.exists()) {
            targetLocation.mkdir();
        }

        String[] children = sourceLocation.list();
        for (int i=0; i<children.length; i++) {
            copyDirectory(new File(sourceLocation, children[i]),
                    new File(targetLocation, children[i]));
        }
    } else {

        InputStream in = new FileInputStream(sourceLocation);
        OutputStream out = new FileOutputStream(targetLocation);

        // Copy the bits from instream to outstream
        byte[] buf = new byte[1024];
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
    }
}