使用JSoup从HTML检索数据

Question

I'm trying to retreive informantions from a website but the problem is that classes names are identical. This is the website structure.

<tr class="main_el">
<td class="key">KEY1</td>
<td class="val">VALUE1</td>
</tr>

<tr class="main_el">
<td class="key">KEY2</td>
<td class="val">VALUE2</td>
</tr>
...
<tr class="main_el">
<td class="key">KEY3</td>
<td class="val">VALUE3</td>
</tr>

I can't use this .get(i).getElementsByClass(); because indexes are diffrent for each page. Please help!

EDIT I want to use KEY1 retrieve VALUE1 only and independently of other VALUES.

Note VALUE1 could be at index 1 or 9

Answer 1

You can write simple function like that.

public Map<String, String> parseHtml(String inputHtml) {
    Document.OutputSettings outputSettings = new Document.OutputSettings();
    outputSettings.syntax(Document.OutputSettings.Syntax.html);
    outputSettings.prettyPrint(false);

    Document htmlDoc = Jsoup.parse(inputHtml);

    //Creating map to save td <key,value>

    Map<String, String> textMap = new HashMap<>();

    Elements trElements = htmlDoc.select("tr.main_el");

    if (trElements.size() > 0) {

        for (Element trElement : trElements) {
            String key = null;
            String value = null;

            for (Element tdElement : trElement.children()) {
                if (tdElement.hasClass("key"))
                    key = tdElement.text();
                if (tdElement.hasClass("value"))
                    value = tdElement.text();
            }

            if (key != null && value != null)
                textMap.put(key, value);
        }


    }
    return textMap;
}

Then you can retrieve values from map by keys from your html.

Thanks.

Answer 2

Maybe this works:

select all <tr> elements
for each <tr>
  select <td> with class "key" from the <tr>
  if value of this element == "KEY1" then
    select <td> with class "key" from <tr>
    do whatever you want with this value