package io.socket.engineio.client.executions; import io.socket.emitter.Emitter; import io.socket.engineio.client.Socket; import java.net.URISyntaxException; public class Connection { public static void main(String[] args) throws URISyntaxException { final Socket socket = new Socket("http://localhost:" + System.getenv("PORT")); socket.on(Socket.EVENT_OPEN, new Emitter.Listener() { @Override public void call(Object... args) { System.out.println("open"); socket.close(); } }); socket.open(); } }