How to use HTMLPARSER in the Java Library to parse the HTML file
How to use HTMLPARSER in the Java class library to resolve HTML files
In Java development, analysis of HTML files is a common task.HTMLPARSER is a popular Java class library that provides the function of data and elements in analysis and extraction of data and elements in HTML documents.This article will introduce how to use HTMLPARSER to resolve HTML files and provide relevant Java code examples.
1. Introduce HTMLPARSER class library
First, you need to introduce the HTMLPARSER class library into your Java project.You can add dependencies by Maven or manually downloading jar files.
For example, if you use maven, you can add the following dependencies to the pom.xml file:
<dependency>
<groupId>net.htmlparser.jericho</groupId>
<artifactId>jericho-html</artifactId>
<version>3.4</version>
</dependency>
2. Create HTMLPARSER object
In the Java code, you first need to create an HTMLPARSER object to load and analyze the HTML file.You can use the following code to implement:
import net.htmlparser.jericho.*;
public class HtmlParserExample {
public static void main(String[] args) {
try {
String htmlfilepath = "path_to_html_file"; // html file path
// Create HTMLPARSER object
Source source = new Source(new File(htmlFilePath));
// Analyze the html file
source = source.getParseText();
// Perform the extraction and processing of HTML data here
// ...
} catch (IOException ioException) {
ioException.printStackTrace();
}
}
}
In the above code, the HTMLPARSER object was created by providing the path of the HTML file.Then, call the `Getparsetext () method to analyze the html file as the source code.
3. Extract and process HTML data
Once the HTML file is parsed to the source code, the method provided by HTMLPARSER to extract and process data and elements in HTML.
Here are some common examples:
-On the extraction of all the hyperlinks:
List<Element> linkElements = source.getAllElements(HTMLElementName.A);
for (Element linkElement : linkElements) {
String href = linkElement.getAttributeValue("href");
String text = linkElement.getTextExtractor().toString();
System.out.println("Link: " + text + " (" + href + ")");
}
-On the link to extract all the picture link:
List<Element> imgElements = source.getAllElements(HTMLElementName.IMG);
for (Element imgElement : imgElements) {
String src = imgElement.getAttributeValue("src");
String alt = imgElement.getAttributeValue("alt");
System.out.println("Image: " + alt + " (" + src + ")");
}
These example code uses the method provided by HTMLPARSER to select specific elements and extract the required attributes and content from these elements.
4. Close HTMLPARSER object
After processing the HTML file, make sure to close the HTMLPARSER object to release resources.You can use the following code to close the HTMLPARSER object:
source.fullSequentialParse();
By calling the `FullsequentialParse () method, you can tell that the HTMLPARSER object has completed the processing of the HTML file.
Summarize
This article introduces how to use the HTMLPARSER class library to analyze the HTML file and provide some common examples of use.By using HTMLPARSER, developers can easily extract and process the required data and elements from HTML.
Please note that the HTMLPARSER class library also provides many other functions and methods, which can be explored and used according to specific needs.It is recommended to check the official documentation in actual development to obtain more details and examples.
