Java Addon V8 -

// Client provides: "user.age > 60 ? 0.9 : (user.transactionAmount > 10000 ? 0.7 : 0.3)" Memory Management is Your Responsibility Unlike Java objects, V8 handles are not garbage collected by the JVM. Each V8Object , V8Array , or V8Function consumes native memory (outside the heap). Failing to call .release() will cause a native memory leak, crashing your JVM with OutOfMemoryError (native).

For decades, the Java Virtual Machine (JVM) has been the gold standard for enterprise-grade backend systems. Its strength lies in static typing, robust multithreading, and unparalleled performance. However, in the modern era of microservices, real-time dashboards, and customizable SaaS platforms, a new need has emerged: dynamic scripting . Java Addon V8

V8 runtime = V8.createV8Runtime(); try { // 1. Register a Java callback (function) inside V8 runtime.registerJavaMethod((receiver, parameters) -> { String name = parameters.getString(0); return "Hello, " + name + " from Java!"; }, "greetFromJava"); // 2. Run JS that calls that Java method String jsCode = "function callJava(name) {" + " return greetFromJava(name);" + "}" + "callJava('Developer');"; // Client provides: "user

What if your rock-solid Java application could execute user-defined logic on the fly? What if you could write business rules in JavaScript, run them at near-native speed, and perfectly bridge the gap between Java objects and JS functions? Each V8Object , V8Array , or V8Function consumes

public void close() { runtime.release(); } }

public double evaluateScore(String jsRule, Object userData) { // Expose userData as a JS object V8Object userObj = new V8Object(runtime); userObj.add("age", userData.getAge()); userObj.add("country", userData.getCountry()); userObj.add("transactionAmount", userData.getAmount()); runtime.add("user", userObj); // Execute the user-provided JS String script = "function calculate() { " + " log('Evaluating user: ' + user.age); " + " let risk = " + jsRule + "; " + " return risk;" + "}; calculate();"; double score = runtime.executeDoubleScript(script); userObj.release(); return score; }

Enter —a collection of projects and techniques that embed Google’s high-performance V8 JavaScript engine directly into the Java ecosystem.