The HTMLPARSER framework guidelines in the Java class library

The HTMLPARSER framework guidelines in the Java class library Introduction: In web development, HTML data often needs to be parsed and processing HTML data.To simplify this process, Java provides various HTMLPARSER frameworks, such as JSOUP, HTMLUNIT and Jericho.This article will focus on the use of the JSOUP framework to help developers process HTML data easier. 1. Introduce JSOUP framework: First of all, you need to introduce the JSOUP framework into your Java project.You can add the following dependencies to the POM.XML file, or manually import the corresponding jar file into the project. <dependency> <groupId>org.jsoup</groupId> <artifactId>jsoup</artifactId> <version>1.13.1</version> </dependency> 2. Analyze HTML data: The JSOUP framework is very simple to resolve HTML data.First of all, we need to obtain the HTML code from the URL or local file and convert it to the Document object. String url = "https://www.example.com"; Document document = jsoup.connect (url) .get (); // Get HTML from the url // or File file = new File("path/to/local/file.html"); Document document = jsoup.parse (file, "UTF-8"); // Get HTML from local files 3. Positioning element: Once we get the Document object of HTML, we can use the CSS selector or XPath expression to locate the required elements. // Use the CSS selector Elements elements = document.select ("" div.container "); // Positioning elements according to CSS class name Element element = document.selectfirst ("h1"); // Position the first element according to the element label // Or use Xpath expression Elements elements = document.select ("// div [contains (@class, 'container')]); // Element element = document.selectfirst ("// h1"); // Position the first element according to the element label 4. Extract data: Once we position the required elements, we can extract the required data from it. // Get the text content of the element String text = element.text(); // Get the attribute value of the element String attributeValue = element.attr("attributeName"); // Ieradant treatment of a set of elements for (Element element : elements) { // Treatment elements } 5. Modify html: In addition to analyzing HTML data, JSOUP also provides the function of modifying HTML.For example, we can add new elements to HTML, modify or delete existing elements. // Add new elements Element newElement = new Element("p"); newElement.text("This is a new paragraph."); document.body().appendChild(newElement); // Modify existing elements element.text("This is the modified text."); // Delete elements element.remove(); Summarize: This article introduces how to use the HTMLPARSER framework in the Java library to analyze and process HTML data.By introducing the JSOUP framework, we can easily extract the required data from HTML, and we can also modify HTML to meet specific needs.Using the example code provided in this article, developers can process HTML data more efficiently.