Introduction to the HTMLPARSER framework in the Java class library
HTML parser is a framework for parsing and processing HTML documents.In the Java library, there are multiple available HTML parser frameworks, and each framework has its own advantages and uses.
Here are the introduction of several commonly used Java HTML parser frameworks:
1. JSOUP: JSOUP is a Java -based HTML parsing library. It provides an API that is easy to use to resolve HTML documents from URL, files or string.With JSOUP, you can easily extract and manipulate HTML elements and its attributes.Here are a sample code that uses JSOUP to analyze HTML documents:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class HtmlParserExample {
public static void main(String[] args) {
String html = "<html> <head> <Title> Example </title> </head> <body> <h1> Welcome
Document document = Jsoup.parse(html);
Element titleElement = document.select("title").first();
String title = titleElement.text();
System.out.println ("Title:" + Title);
Element headingElement = document.select("h1").first();
String heading = headingElement.text();
System.out.println ("Title:" + Heading);
}
}
2. HTML Parser: HTML Parser is another popular Java HTML parser framework. It provides a simple API for extracting data from HTML documents.Unlike JSOUP, HTML Parser can also process incomplete or invalid HTML documents.The following is an example code that uses HTML PARSER to analyze HTML documents:
import org.htmlparser.Node;
import org.htmlparser.Parser;
import org.htmlparser.filters.TagNameFilter;
import org.htmlparser.util.NodeList;
public class HtmlParserExample {
public static void main(String[] args) {
String html = "<html> <head> <Title> Example </Title> </Head> <body> <H1> Welcome
try {
Parser parser = new Parser(html);
TagNameFilter titleFilter = new TagNameFilter("title");
NodeList titleNodes = parser.extractAllNodesThatMatch(titleFilter);
Node titleNode = titleNodes.elementAt(0);
String title = titleNode.toPlainTextString();
System.out.println ("Title:" + Title);
TagNameFilter headingFilter = new TagNameFilter("h1");
NodeList headingNodes = parser.extractAllNodesThatMatch(headingFilter);
Node headingNode = headingNodes.elementAt(0);
String heading = headingNode.toPlainTextString();
System.out.println ("Title:" + Heading);
} catch (Exception e) {
e.printStackTrace();
}
}
}
This is just a brief introduction to the two available Java HTML parser frameworks.According to your needs and preferences, you can choose the framework suitable for your project.No matter which framework you choose, the HTML parser can help you easily extract and process data from the HTML document.
