Generating a tone using TeaVM, Webassembly in Java

Question

I've adapted this Java class and it's compiling with TeaVM, the text output is good so the thing is running, but I can't get it to generate a sound.

package com.xyz;

import org.teavm.jso.dom.html.HTMLDocument;
import org.teavm.jso.webaudio.AudioContext;
import org.teavm.jso.webaudio.OscillatorNode;

public class Client {
    public static void main(String[] args) throws InterruptedException {
        var document = HTMLDocument.current();
        var div = document.createElement("div");
        div.appendChild(document.createTextNode("TeaVM generated element 3"));
        document.getBody().appendChild(div);
        
        var audioContext = AudioContext.create();
        OscillatorNode oscillator = audioContext.createOscillator();
        var g = audioContext.createGain();
        oscillator.setType(OscillatorNode.TYPE_SINE);
        oscillator.connect(g);
        g.connect(audioContext.getDestination());
        oscillator.start(0);
        Thread.sleep(10000);
        oscillator.stop(20000);
        Thread.sleep(10000);
    }
}

Answer 1

Okay, in this case it was the media autoplay policy in chrome:

https://developer.chrome.com/blog/autoplay/#webaudio

Workaround by starting with parameters:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --autoplay-policy=no-user-gesture-required

Hopefully in my finished app the user will have interacted with the page before the sounds are played and Chrome won't see it as a problem. I should have checked the warnings in the developer tools to find this one.