java - 使用 JSoup 从 HTML 中提取图像类型

Question

如何使用 JSoup 从 url 中提取图像类型？我正在解析一个 html，它可以发送图像 url(使用 asbUrl() )。但是，我需要测试它的类型。现在，它使所有内容都变成了 .png，这显然不适用于大多数类型。有什么想法吗？

Answer 1

首先将图像保存在文件中。这里有一些代码可以帮助您做到这一点:

public class DownloadImages {

    //The url of the website. This is just an example
    private static final String webSiteURL = "http://www.supercars.net/gallery/119513/2841/5.html";

    //The path of the folder that you want to save the images to
    private static final String folderPath = "<FOLDER PATH>";

    public static void main(String[] args) {

        try {

            //Connect to the website and get the html
            Document doc = Jsoup.connect(webSiteURL).get();

            //Get all elements with img tag ,
            Elements img = doc.getElementsByTag("img");

            for (Element el : img) {

                //for each element get the srs url
                String src = el.absUrl("src");

                System.out.println("Image Found!");
                System.out.println("src attribute is : "+src);

                getImages(src);

            }

        } catch (IOException ex) {
            System.err.println("There was an error");
            Logger.getLogger(DownloadImages.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private static void getImages(String src) throws IOException {

        String folder = null;

        //Exctract the name of the image from the src attribute
        int indexname = src.lastIndexOf("/");

        if (indexname == src.length()) {
            src = src.substring(1, indexname);
        }

        indexname = src.lastIndexOf("/");
        String name = src.substring(indexname, src.length());

        System.out.println(name);

        //Open a URL Stream
        URL url = new URL(src);
        InputStream in = url.openStream();

        OutputStream out = new BufferedOutputStream(new FileOutputStream( folderPath+ name));

        for (int b; (b = in.read()) != -1;) {
            out.write(b);
        }
        out.close();
        in.close();

    }

当您将图像保存在磁盘上时，您可以像这样找到它们的扩展名:

String extension = FilenameUtils.getExtension("/path/to/file/image.png");

完成后，也使用 Java 删除文件。

我不确定如何直接从 URL 获取扩展