如何选择段落中特定h3 (也有id和span类)后面的所有链接。

Question

我试图从http://virt10.itu.chalmers.se/index.php/Guard获取所有链接(更精确的链接文本)，只要它们在标题下的“关系”，“可以实例化”。

<h2><span class="mw-headline" id="Relations">Relations</span></h2>
<h3><span class="mw-headline" id="Can_Instantiate">Can Instantiate</span></h3>
<p><a href="/index.php/Attention_Demanding_Gameplay" title="Attention Demanding Gameplay">Attention Demanding Gameplay</a>, 
<a href="/index.php?title=Conflicts&amp;action=edit&amp;redlink=1" class="new" title="Conflicts (page does not exist)">Conflicts</a>, 
<a href="/index.php/Continuous_Goals" title="Continuous Goals">Continuous Goals</a>, 
<a href="/index.php?title=Ownership&amp;action=edit&amp;redlink=1" class="new" title="Ownership (page does not exist)">Ownership</a>, 
<a href="/index.php/Preventing_Goals" title="Preventing Goals">Preventing Goals</a>, 
<a href="/index.php/Reconnaissance" title="Reconnaissance">Reconnaissance</a>, 
<a href="/index.php/Stimulated_Planning" title="Stimulated Planning">Stimulated Planning</a>, 
<a href="/index.php/Trade-Offs" title="Trade-Offs">Trade-Offs</a>
</p>

不幸的是，我有点不理解jsoup (或java)。到目前为止，我已经尝试过这样的东西

Elements contentinstantiate = doc.select("span.mw-headline, h3 ~ a");

for (int i=0; i < contentinstantiate.size(); i++) {
    System.out.println(contentinstantiate.get(i).text());
}

或

Elements links = content.getElementsByTag("a");

for (Element link : links) {
    String linkHref = link.attr("title");
    System.out.println(linkHref);
    String linkText = link.text();
    System.out.println(linkText);
}

但两者都不起作用，我在这里有点不知所措。有谁可以帮我？

Answer 1

您选择了h3，而h3没有任何标签。我想你必须选择p标签。

Answer 2

Jsoup下一个兄弟API将会帮助你。您需要选择

<h2><span class="mw-headline" id="Relations">Relations</span></h2> 

然后您需要迭代到下一个元素，它将是h3。

<h3><span class="mw-headline" id="Can_Instantiate">Can Instantiate</span></h3> 

然后，您将转到下一个兄弟，并检查段落节点

一旦选择了段落节点，提取链接就很容易了

例如，H2的下一个同级节点是H3，H3的下一个同级节点是<p>

每个Jsoup节点都有下面的方法

public Node nextSibling​()

，它将把它迭代到下一个同级

你可以在Jsoup doc上阅读它。

Answer 3

试试这个，这是我的工作代码：

final String url = "http://virt10.itu.chalmers.se/index.php/Guard";
         Document doc = Jsoup.connect(url).get();
         Element contentinstantiate = doc.getElementById("Can_Instantiate").parent().nextElementSibling();
         for(Element e : contentinstantiate.getAllElements()){
             System.out.println(e.text());
         }

输出：

Attention Demanding Gameplay, Conflicts, Continuous Goals, Ownership, Preventing Goals, Reconnaissance, Stimulated Planning, Trade-Offs
Attention Demanding Gameplay
Conflicts
Continuous Goals
Ownership
Preventing Goals
Reconnaissance
Stimulated Planning
Trade-Offs