java - JSOUP .attr() 方法不从工作 html 中提取数据

Question

我的 .attr 方法存在问题，该方法不适用于除“class”之外的所有属性。 我尝试提取“alt”属性来获取商店的名称，但它不起作用。对“src”和“data-original”进行了相同的尝试，但没有打印出任何内容。

这是我用来提取数据的完整方法。

public List<String> getShops() {
        Elements elements = document.select(".store-logo");
        System.out.println(elements.html());
       for(Element image : elements){
           System.out.println(image.attr("alt"));
       }
        return null;
    }

为了确保我没有使用空文档，我为所有看起来像这样的元素打印了整个 HTML:

<img src="//image.ceneostatic.pl/imageschain/data/shops_s/20853/logo.jpg;data/custom_images/590/custom_image.png" alt="nalepsze.pl">
<img src="/content/img/icons/pix-empty.png" alt="allegro.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/20136/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="avans.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/18601/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="proshop.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/29068/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="g2a.com" data-original="//image.ceneostatic.pl/imageschain/data/shops/23040/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="fotosoft.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/3914/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="techsat24.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/5666/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="imperiumpc.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/12579/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="domsary.eu" data-original="//image.ceneostatic.pl/imageschain/data/shops/4725/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="net-s.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/3653/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="sferis.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/4614/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="morele.net" data-original="//image.ceneostatic.pl/imageschain/data/shops/379/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="zakupy.vip" data-original="//image.ceneostatic.pl/imageschain/data/shops/29402/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="fotoelektro.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/1671/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="3kropki.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/357/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="electro.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/16202/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="allegro.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/20136/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="avans.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/18601/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">
<img src="/content/img/icons/pix-empty.png" alt="proshop.pl" data-original="//image.ceneostatic.pl/imageschain/data/shops/29068/logo.jpg;data/custom_images/585/custom_image.png" class="js_lazy">

此提取中的数据是正确的，但每个循环中的下一步不起作用，我为每个元素得到一个空字符串，这很奇怪，因为我可以提取“类”属性。

我非常感谢根据该主题提供的任何提示。

PS。 jsoup 版本是 1.11.3

Answer 1

在您的示例中，您使用类“store-logo”，但在附加的 html 文档中，没有一个 img 元素具有此类。将类名替换为“js_lazy”时，您的代码会提取 alt 属性。