Java Socket not using proxy from JAVA_TOOL_OPTIONS

How to make all Java connections to use proxy provided via JAVA_TOOL_OPTIONS environment variable?

The simple app I'm using as a test is taken from GitHub:

package to.noc.sslping;

import javax.net.ssl.SSLParameters;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import java.io.OutputStream;
public class SSLPing {

    public static void main(String[] args) {
        if (args.length != 2) {
            System.out.println("Usage: java -jar SSLPing.jar <host> <port>");
            System.exit(1);
        }
        try {

            String hostname = args[0];
            int port = Integer.parseInt(args[1]);

            System.out.println("About to connect to '" + hostname + "' on port " + port);

            SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
            SSLSocket sslsocket = (SSLSocket) sslsocketfactory.createSocket(hostname, port);

            // Hostname verification is not done by default in Java with raw SSL connections.
            // The next 3 lines enable it.
            SSLParameters sslParams = new SSLParameters();
            sslParams.setEndpointIdentificationAlgorithm("HTTPS");
            sslsocket.setSSLParameters(sslParams);

            // we only send 1 byte, so don't buffer
            sslsocket.setTcpNoDelay(true);

            // Write a test byte to trigger the SSL handshake
            OutputStream out = sslsocket.getOutputStream();
            out.write(1);

            // If no exception happened, we connected successfully
            System.out.println("Successfully connected");

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

What I want is to be able to provide the PROXY settings via environment variables without having to configure it in the Java code. I found that it is possible to provide some settings via the JAVA_TOOL_OPTIONS env.

JAVA_TOOL_OPTIONS="-Dhttp.proxyHost=161.xxx.xxx.xxx
                   -Dhttp.proxyPort=8080
                   -Dhttp.proxySet=true
                   -Dhttps.proxyHost=161.xxx.xxx.xxx
                   -Dhttps.proxyPort=8080
                   -Dhttps.proxySet=true"

It is correctly seen by the command

java -jar SSLPing.jar google.com 443
Picked up JAVA_TOOL_OPTIONS: -Dhttp.proxyHost=161.xxx.xxx.xxx
                   -Dhttp.proxyPort=8080
                   -Dhttp.proxySet=true
                   -Dhttps.proxyHost=161.xxx.xxx.xxx
                   -Dhttps.proxyPort=8080
                   -Dhttps.proxySet=true
About to connect to 'google.com' on port 443
Successfully connected

However when I need to reach a particular URL that requires the proxy, it fails to connect.

How do I make any socket to use the proxy from JAVA_TOOL_OPTIONS env? How to check if the sockets are using the proxy?