How can I extract data from HTML documents using Java?

Java HTML Parsing

To obtain data from a website, you must first understand the structure of the HTML document. HTML elements are organized using tags, which specify the type and content of each element.

For example, the following HTML represents a div tag with a specific CSS class:

<code class="html"><div class="classname"></div></code>

To locate and retrieve data from this tag in Java, you can use a Java HTML parser library. One option is jsoup, which allows for convenient HTML parsing using jQuery-like syntax:

<code class="java">import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

String html = "<div class=\"classname\">Data to be scraped</div>";
Document doc = Jsoup.parse(html);

boolean usesClass = doc.select("div.classname").hasAttr("class");
String text = doc.select("div.classname").text();
String link = doc.select("div.classname").attr("href");</code>

With jsoup, you can easily check if an element has a specific class, retrieve its text content, or obtain any attributes it may have.

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