Failed to resolve Adobe's artifact from public the repository for developing new AEM's package

Hi guys,

I'm going to develop a AEM's UI package project from the official development site: 

http://docs.adobe.com/content/docs/en/cq/current/developing/developmenttools/how-to-build-aem-projects-using-apache-maven.html

However, the build was failed because the link below is not found:

https://repo.adobe.com/nexus/content/groups/public/org/apache/maven/plugins/maven-metadata.xml

So i think the Adobe's public repository is being down or have a problem in it.

Can anyone please help me with this?

Thanks,

tnguyen