Examples and practice of the Attoparser framework in the Java class library
Attoparser is a Java class library for analysis of HTML and XML documents.It provides a simple and effective way to extract and operate data in these documents.Here are examples and practice of using the Attoparser framework.
1. Introduce the Attoparser Library
First, you need to add the Attoparser library to the Java project.The following dependencies can be added to the construction tools such as Maven or Gradle:
<dependency>
<groupId>org.attoparser</groupId>
<artifactId>attoparser</artifactId>
<version>2.0.4.RELEASE</version>
</dependency>
2. Analyze the HTML document
The following is a simple example. Demonstration of how to use Attoparser to resolve HTML documents and extract the title and paragraph content:
import org.attoparser.simple.*;
public class HtmlParserExample {
public static void main(String[] args) throws Exception {
String html = "<html><body><h1>Title</h1><p>Paragraph 1</p><p>Paragraph 2</p></body></html>";
IHtmlParser htmlParser = new AttoParserBuilderFactory().getHTMLParser();
HtmlHandler htmlHandler = new HtmlHandler();
htmlParser.parse(html, htmlHandler);
System.out.println("Title: " + htmlHandler.getTitle());
System.out.println("Paragraphs: " + htmlHandler.getParagraphs());
}
private static class HtmlHandler extends AbstractSimpleMarkupHandler {
private StringBuilder currentElementContent = new StringBuilder();
private StringBuilder title = new StringBuilder();
private List<String> paragraphs = new ArrayList<>();
public void handleOpenElement(final String elementName, final List<String> attrs) {
// Turn the open label of the element
currentElementContent = new StringBuilder();
}
public void handleText(final char[] text, final int textLen) {
// Treatment element content text
currentElementContent.append(text, 0, textLen);
}
public void handleCloseElement(final String elementName) {
// Treat the closure label of the element
if (elementName.equals("h1")) {
title.append(currentElementContent);
} else if (elementName.equals("p")) {
paragraphs.add(currentElementContent.toString());
}
}
public String getTitle() {
return title.toString();
}
public List<String> getParagraphs() {
return paragraphs;
}
}
}
In the above example, we created a HTMLHANDLER class that inherited from ABSTRACTSIMPLEMARKUPHANDLER and rewritten the method of this class to handle HTML marks.In the handleopeenelement method, we initialized the StringBuilder object for preserving the content of the current element.In the handletext method, we add the text of the element content to the StringBuilder object of the current element content.In the HandleCloseElement method, we decide whether the content is the title or paragraph according to the name of the element, and save it into the corresponding variable.Finally, in the Main method, we created instances of the HTMLPARSEREXAMPLE class, using Attoparser to analyze the HTML document, and obtained the extracted title and paragraph content from the HTMLHANDLER class and printed them.
Through the above examples, how to use the ATTOPARSER framework to parse the HTML document and extract the data.The HTMLHANDLER class can be extended as needed to extract more content or perform other operations.
