eleinadani

// HTTP request handler
WebServer.create(configuration, route.get("/request", (req, res) -> {
  //  ( #1 )  An HTTP GET request is received. Get some request data
  int requestId = getRequestId(req);
  // Send the data to JavaScript. Perform computation in JS and
  // send back to the HTTP client a response message when done.
  executeJs(requestId).whenComplete((r, ex) -> {
    if (ex != null) {
        res.status(404)
           .send("404 error");

eleinadani

// Expose a JS asynchronous function to Java
Value asyncFunction = context.eval("js", "(async function(x) { return x; })");
// Invoke the function. The result is a JavaScript Promise object
Value jsPromise = asyncFunction.execute(42);
// Register promise reactions
jsPromise.invokeMember("then", (Consumer<Object>) (result) -> {
  System.out.println("JavaScript resolves: " + result);
})
.invokeMember("catch", (Consumer<Throwable>) (error) -> {
  System.out.println("JavaScript rejects: " + error);

eleinadani

async function() {
  // a Java object implementing the `then` method
  let javaTrampoline = ... // created from Java
  // create a JavaScript promise
  let interopPromise = new Promise(javaTrampoline);
  // register some promise reactions
  try {
    // await for the “interop” promise to resolve
    let result = await interopPromise;
    console.log('Java resolves: ' + result);

eleinadani

public class ThenableObject {
  void then(Value resolve, Value reject) {
    try {
      Object someResult = computeSomething();
      resolve.executeVoid(someResult);
    } catch (Throwable t) {
      reject.executeVoid(t);
    }
  }
}

eleinadani

// a Java object implementing the `then` method (created from Java)
let javaExecutor = Java.type('some.awesome.Klass').createNew();
// create a JavaScript promise
let interopPromise = new Promise(javaExecutor);
// register some promise reactions
interopPromise.then(result => { console.log('Java resolves: ' + result); },
                    error => { console.log('Java rejects: ' + error); });

eleinadani

void then(Value resolve, Value reject);

eleinadani

$ SKIP_JACOCO=true mvn test -Dtest=io.reactiverse.es4x.test.StackTraceTest 
[INFO] Scanning for projects...
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building es4x 0.11.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-enforcer-plugin:1.4.1:enforce (enforce-maven) @ es4x ---
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.5:prepare-agent (default) @ es4x ---

eleinadani

public class AwesomeClass {
  // a concurrent queue shared with Node
  private final Queue<Object> queue;
  
  public AwesomeClass(Queue<Object> queue) {
    this.queue = queue;
  }
  
  public void start() {
    Thread thread = new Thread(new Runnable() {

eleinadani

function JavaToJSNotifier {
  this.queue = new java.util.concurrent.LinkedBlockingDeque();
  this.worker = new Worker(`
      const { workerData, parentPort } = require('worker_threads');
      while (true) {
        // block the worker waiting for the next notification from Java
        var data = workerData.queue.take();
        // notify the main event loop that we got new data 
        parentPort.postMessage(data);
      }`,

eleinadani

let w = new Worker(`
        const { parentPort } = require('worker_threads');
        parentPort.on('message', (m) => {
          const x = m.random.nextInt(100);
          const y = m.random.nextInt(100);
          var Point = Java.type('java.awt.Point');
          parentPort.postMessage(new Point(x,y));
        });
`, {eval:true});