首页 \ 问答 \ JSoup查询：如何在另一个标记中查找HTML标记的所有实例(JSoup query: how to find all instances of an HTML tag in another tag)

JSoup查询：如何在另一个标记中查找HTML标记的所有实例(JSoup query: how to find all instances of an HTML tag in another tag)

 我有一个HTML页面来扫描标题和图形元素。 HTML文件的代码是：  
<body>
<section>
    <h2>H2-1</h2>
    <div>
        <section>
            <h3>H3-1</h3>
            <div>
                <figure><img src="Fig 1.png"></figure>
            </div>
        </section>
        <section>
            <h3>H3-2</h3>
            <div></div>
        </section>
    </div>
</section>
<section>
    <h2>H2-2</h2>
    <div>
        <figure><img src="Fig 2.png"></figure>
        <figure><img src="Fig 3.png"></figure>
        <figure><img src="Fig 4.png"></figure>
    </div>
</section>
<section>
    <h2>H2-3</h2>
    <div>
        <figure><img src="Fig 5.png"></figure>
        <section>
            <h3>H3-3</h3>
            <div><figure><img src="Fig 6.png"></figure></div>
        </section>
    </div>
</section>
<section>
    <h2>H2-4</h2>
    <div>
    </div>
</section>
</body>
 
 我想要的输出是：  
H2-1
  H3-1
    Fig 1
H2-2
  Fig 2
  Fig 3
  Fig 4
H2-3
  Fig 5
  H3-3
    Fig 6
 
 我想找到显示所有具有子图元素的标题。 如果它具有直接子图形元素，我不想显示标题。  
 我正在尝试的JSoup代码是：  
Document doc = Jsoup.parse(sourceCode);
Elements sectionTags = doc.body().getElementsByTag("section");
for (Element sectTag : sectionTags)
{
  System.out.println (sectTag.children().first().ownText());  //print the Heading text 
  Elements figureTags = sectTag.getElementsByTag("figure");
  for (Element figTag : figureTags) 
  {
    System.out.println (figTag.getElementsByTag("img").attr("src").toString());  // print the image name
  }                          
}
 
 但我没有得到理想的输出。 我得到的输出是：  
H2-1
  Fig 1
  H3-1
    Fig 1
H2-2
  Fig 2
H2-3
  Fig 5
  H3-3
    Fig 6
 
 有帮助吗？ 我是JSoup的新手，感谢任何有用的建议或提示。  
 提前致谢。 

I have an HTML page to scan for headings and figure elements. The code of the HTML file is: 
<body>
<section>
    <h2>H2-1</h2>
    <div>
        <section>
            <h3>H3-1</h3>
            <div>
                <figure><img src="Fig 1.png"></figure>
            </div>
        </section>
        <section>
            <h3>H3-2</h3>
            <div></div>
        </section>
    </div>
</section>
<section>
    <h2>H2-2</h2>
    <div>
        <figure><img src="Fig 2.png"></figure>
        <figure><img src="Fig 3.png"></figure>
        <figure><img src="Fig 4.png"></figure>
    </div>
</section>
<section>
    <h2>H2-3</h2>
    <div>
        <figure><img src="Fig 5.png"></figure>
        <section>
            <h3>H3-3</h3>
            <div><figure><img src="Fig 6.png"></figure></div>
        </section>
    </div>
</section>
<section>
    <h2>H2-4</h2>
    <div>
    </div>
</section>
</body>
 
The output I want is: 
H2-1
  H3-1
    Fig 1
H2-2
  Fig 2
  Fig 3
  Fig 4
H2-3
  Fig 5
  H3-3
    Fig 6
 
I want to find show all headings that has a child figure element. I do not want to display the heading if it does to have an immediate child figure element. 
The JSoup code I am trying is: 
Document doc = Jsoup.parse(sourceCode);
Elements sectionTags = doc.body().getElementsByTag("section");
for (Element sectTag : sectionTags)
{
  System.out.println (sectTag.children().first().ownText());  //print the Heading text 
  Elements figureTags = sectTag.getElementsByTag("figure");
  for (Element figTag : figureTags) 
  {
    System.out.println (figTag.getElementsByTag("img").attr("src").toString());  // print the image name
  }                          
}
 
but I am not getting the desired output. The output that I get is: 
H2-1
  Fig 1
  H3-1
    Fig 1
H2-2
  Fig 2
H2-3
  Fig 5
  H3-3
    Fig 6
 
Any help? I am new to JSoup and appreciate any suggestion or tip that can work.  
Thanks in advance.

原文：https://stackoverflow.com/questions/37682061

更新时间：2023-11-01 06:11

最满意答案

 在这两种情况下你都做错了： malloc和calloc 。  
 malloc将分配您告诉它的字节数。  
 你调用malloc(sizeof(member_size)) ： 
 变量member_size类型为size_t （或多或少为int ）。 
 sizeof(size_t)是4个字节（在许多平台上）。 
 因此， sizeof(member_size)是4个字节，您正在调用malloc(4) 。  
 我认为你不想要4个字节。 
 我想你想要malloc(nmember * member_size)  
 
 同样，对于calloc，你想要： 
calloc(nmember, member_size) 
 
 我不知道为什么你没有充分理由抛出随机sizeof电话。 

You are doing it wrong in both cases: malloc and calloc. 
malloc will allocate the number of bytes you tell it to. 
You call malloc(sizeof(member_size)):
 Variable member_size has type size_t (more-or-less an int).
 sizeof(size_t) is 4-bytes (on many platforms).
 So, sizeof(member_size) is 4-bytes, and you are calling malloc(4).  
I don't think you want 4 bytes.
 I think you want malloc(nmember * member_size) 
 
 Similarly, for calloc, you want: 
calloc(nmember, member_size) 
 
I don't know why you're throwing in random sizeof calls for no good reason.

JSoup查询：如何在另一个标记中查找HTML标记的所有实例(JSoup query: how to find all instances of an HTML tag in another tag)

最满意答案

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