java 如何使用 Jsoup 从相对 HTML 链接中提取绝对 URL？
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How to extract absolute URL from relative HTML links using Jsoup?
提问by sundhar
I am using Jsoupto extract URL of an webpage. The hrefattribute of those URL's are relative like:
我正在使用Jsoup来提取网页的 URL。在href这些URL的属性是相对的，如：
<a href="/text">example</a>
Here is my attempt:
这是我的尝试：
Document document = Jsoup.connect(url).get();
Elements results = document.select("div.results");
Elements dls = results.select("dl");
for (Element dl : dls) {
String url = dl.select("a").attr("href");
}
This works fine, but if I use
这工作正常，但如果我使用
String url = dl.select("a").attr("abs:href");
to get the absolute URL like http://example.com/text, it is not working. How can I get the absolute URL?
要获取绝对 URL 之类的http://example.com/text，它不起作用。如何获取绝对网址？
采纳答案by BalusC
You need Element#absUrl().
你需要Element#absUrl().
String url = dl.select("a").absUrl("href");
You can by the way shorten the select:
您可以顺便缩短选择：
Document document = Jsoup.connect(url).get();
Elements links = document.select("div.results dl a");
for (Element link : links) {
String url = link.absUrl("href");
}
回答by tindase
String url = dl.select("a").absUrl("href");
String url = dl.select("a").absUrl("href");
Is not correct because dl.select("a")will not return a single item but a collection.
You need to get elements by index
不正确，因为dl.select("a")不会返回单个项目而是一个集合。您需要通过索引获取元素
eg :
例如：
Elements elems = dl.select("a");
Element a1 = elems.get(0); //0 is the index first element increasing to (elems.size()-1)
now you can do
a1.absUrl("href");
If you are sure only one item will result from the select above, or that the item you want will be the first, you can:
如果您确定上面的选择只会产生一个项目，或者您想要的项目将是第一个，您可以：
String url = dl.select("a").get(0).absUrl("href");
Which is also same as
这也与
String url = dl.select("a").first().absUrl("href");
It doesn't have to be the first element anyway, you can always replace the 0 in
String url = dl.select("a").get(0).absUrl("href");with the index of your element.
Or use a select that is more specific that will only result in one element.
无论如何，它不必是第一个元素，您始终可以将 0 替换为
String url = dl.select("a").get(0).absUrl("href");元素的索引。或者使用更具体的选择，只会产生一个元素。
