private static void downloadFileFromURL(String urlString, File destination) throws Exception {
        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
            String username = System.getenv("MVNW_USERNAME");
            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
            Authenticator.setDefault(new Authenticator() {
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(username, password);
                }
            });
        }
        URL website = new URL(urlString);
        ReadableByteChannel rbc;
        rbc = Channels.newChannel(website.openStream());
        FileOutputStream fos = new FileOutputStream(destination);
        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
        fos.close();
        rbc.close();
    }
Name of the property which should be used to override the default download url for the wrapper.
.mvn/wrapper/MavenWrapperDownloader.java