JVMJavaScript

JVMJavaScript refers to the ability to run JavaScript code on the Java Virtual Machine (JVM). This is typically achieved through specific JavaScript engines that are implemented in Java and designed to execute within the JVM environment. The most prominent example of this technology is Nashorn, which was a high-performance JavaScript engine developed by Oracle for the JVM. Prior to Nashorn, Rhino was another popular JavaScript engine that served a similar purpose.

The primary benefit of running JavaScript on the JVM is the ability to leverage Java's extensive libraries and existing infrastructure. JavaScript code executing on the JVM can seamlessly interact with Java objects and classes, allowing developers to combine the strengths of both languages. This can be particularly useful for tasks such as scripting within Java applications, developing server-side JavaScript applications that benefit from Java's performance and concurrency features, or integrating JavaScript logic into existing Java codebases.

Nashorn, for instance, offered features like ECMAScript 5.1 and later ECMAScript 2015 (ES6) compatibility, along with significant performance improvements over its predecessor. While Nashorn was removed from the JDK starting with Java 15, the concept of running JavaScript on the JVM remains relevant, and alternative engines or approaches may be used to achieve similar interoperability. This technology bridges the gap between the dynamic nature of JavaScript and the robust, platform-independent environment provided by the JVM.