Nashorn is a JavaScript engine for the Java Virtual Machine (JVM) that was introduced in Java 8 as a replacement for the earlier Rhino JavaScript engine. Nashorn provides the capability to execute JavaScript code within a Java application, making it a useful tool for embedding JavaScript functionality and scripting into Java applications.
JavaScript Engine: Nashorn is a full-featured JavaScript engine that complies with the ECMAScript 5.1 standard. It allows you to execute JavaScript code directly from Java applications.
Integration: Nashorn is tightly integrated with the Java platform, which means you can seamlessly interact with Java classes, objects, and APIs from your JavaScript code.
Performance: One of Nashorn’s key improvements over Rhino is its superior performance. Nashorn uses just-in-time (JIT) compilation, which can make JavaScript execution faster than with the earlier Rhino engine.
Command-Line Tool: Nashorn provides a command-line tool called jjs that allows you to run JavaScript code from the command line.
Embeddable: You can embed Nashorn into your Java applications to execute JavaScript code, handle scripting tasks, and create extensible applications.
Here’s a basic example of using Nashorn to execute JavaScript code from a Java application:
Here’s a basic example of using Nashorn to execute JavaScript code from a Java application:
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
public class NashornExample {
public static void main(String[] args) {
ScriptEngineManager engineManager =
new ScriptEngineManager();
ScriptEngine engine =
engineManager.getEngineByName("nashorn");
try {
// Execute JavaScript code
engine.eval
("var greeting = 'Hello, Nashorn!'; print(greeting);");
} catch (ScriptException e) {
e.printStackTrace();
}
}
}
In the example above, we use the javax.script package to create a ScriptEngine with the Nashorn engine. We then use engine.eval to execute a simple JavaScript code snippet, which prints “Hello, Nashorn!” to the console.
