HTTP server integration example for java-ngrok, full documentation found at https://javadoc.io/doc/com.github.alexdlaird/java-ngrok/latest/index.html

JavaNgrokHTTPServerExample.java

package com.github.alexdlaird;

import com.github.alexdlaird.ngrok.NgrokClient;
import com.github.alexdlaird.ngrok.protocol.CreateTunnel;
import com.github.alexdlaird.ngrok.protocol.Tunnel;
import com.sun.net.httpserver.HttpServer;

import java.net.InetSocketAddress;
import java.util.logging.Logger;

public class NgrokHttpServer {

    private static final Logger LOGGER = Logger.getLogger(String.valueOf(NgrokHttpServer.class));

    public static void main(String[] args) throws Exception {
        final int port = Integer.parseInt(System.getenv().getOrDefault("PORT", "80"));

        final HttpServer server = HttpServer.create(new InetSocketAddress(port), 0);

        final NgrokClient ngrokClient = new NgrokClient.Builder().build();

        final CreateTunnel createTunnel = new CreateTunnel.Builder()
                .withAddr(port)
                .build();
        final Tunnel tunnel = ngrokClient.connect(createTunnel);

        LOGGER.info(String.format("ngrok tunnel \"%s\" -> \"http://127.0.0.1:%d\"", tunnel.getPublicUrl(), port));

        server.start();
    }
}