In this blog post, we will explore Nashorn, a JavaScript engine that is embedded in JDK 8 and later versions. Nashorn provides a powerful tool for server-side scripting and automation tasks.

Table of Contents

• What is Nashorn?
• Using Nashorn for Server-Side Scripting
• Automating tasks with Nashorn
• Conclusion

What is Nashorn?

Nashorn is a JavaScript engine for the Java Virtual Machine (JVM) that allows developers to execute JavaScript on the server-side. It was introduced in JDK 8 as a replacement for the Rhino JavaScript engine.

Nashorn provides seamless interoperability between Java and JavaScript, making it easy to integrate JavaScript code with existing Java applications. It supports the latest ECMAScript 5.1 standard and includes several performance enhancements over Rhino.

Using Nashorn for Server-Side Scripting

With Nashorn, developers can write server-side scripts in JavaScript instead of using traditional languages like Java or PHP. This enables rapid prototyping and facilitates the development of simple server applications.

To use Nashorn for server-side scripting, you can create a Java class that embeds the Nashorn engine and executes JavaScript code. Here’s an example:

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

public class NashornExample {
    public static void main(String[] args) {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("nashorn");

        try {
            engine.eval("print('Hello from Nashorn!');");
        } catch (ScriptException e) {
            e.printStackTrace();
        }
    }
}

In this example, we create an instance of ScriptEngine for Nashorn, and then use the eval() method to execute a simple JavaScript code that prints “Hello from Nashorn!”.

Automating tasks with Nashorn

Nashorn’s scripting capabilities can also be utilized for automating various tasks, such as batch processing, data manipulation, or even building command-line tools.

For example, let’s say you want to automate the process of resizing images in a directory. You can write a JavaScript script using Nashorn that leverages a Java library like ImageMagick to resize the images. Here’s an example:

var directory = "/path/to/images/";
var files = new java.io.File(directory).listFiles();

for (var i = 0; i < files.length; i++) {
    if (files[i].isFile()) {
        // Resize the image using ImageMagick
        // ...
    }
}

With Nashorn, you have the power of JavaScript and the flexibility of Java libraries at your fingertips, making it easy to automate various tasks on the server-side.

Conclusion

Nashorn is a powerful tool for server-side scripting and automation tasks. With its seamless integration with Java and support for the latest ECMAScript standard, developers can leverage the strengths of both languages to build efficient and flexible server applications.

Whether you’re building a web application, automating tasks, or prototyping server-side logic, Nashorn provides a reliable and efficient solution. Give it a try and see how it can enhance your server-side scripting and automation workflows.

#JavaScript #ServerSideScripting