jsoup extract JavaScript from HTML script element in Java

Introduction

In this post, we are going to explore how to use the jsoup library in a Java application to extract JavaScript content of a script element in the HTML document.

Add jsoup library to your Java project

To use jsoup Java library in the Gradle build project, add the following dependency into the build.gradle file.

compile 'org.jsoup:jsoup:1.13.1'

To use jsoup Java library in the Maven build project, add the following dependency into the pom.xml file.

<dependency>
    <groupId>org.jsoup</groupId>
    <artifactId>jsoup</artifactId>
    <version>1.13.1</version>
</dependency>

To download the jsoup-1.13.1.jar file you can visit jsoup download page at jsoup.org/download

Sample HTML File

For example, we have a sample.html file as below.

<!DOCTYPE html>
<html>
<body>
<h1>Simple Solution</h1>
<script>
    let hello = 'hello';
</script>
</body>
</html>

Extract JavaScript from script element

To get the script content of a script tag we can use Element.data() method as following Java example program.

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import java.io.File;
import java.io.IOException;

public class ExtractJavaScriptExample {
    public static void main(String... args) {
        try {
            String fileName = "sample.html";
            File file = new File(fileName);
            Document document = Jsoup.parse(file, "UTF-8");
            Elements elements = document.getElementsByTag("script");
            Element scriptElement = elements.first();

            String script = scriptElement.data();

            System.out.println(script);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}