in maven-wrapper/src/main/java/org/apache/maven/wrapper/DefaultDownloader.java [76:87]
public void download(URI address, Path destination) throws Exception {
if (Files.exists(destination)) {
return;
}
Files.createDirectories(destination.getParent());
if (!"https".equals(address.getScheme())) {
Logger.warn("Using an insecure connection to download the Maven distribution."
+ " Please consider using HTTPS.");
}
downloadInternal(address, destination);
}