<mirror>  
      <id>mirrorId</id>  
      <mirrorOf>repositoryId</mirrorOf>  
      <name>Human Readable Name for this Mirror.</name>  
      <url>http://my.repository.com/repo/path</url>   

</mirror>

<mirror>    
      <id>central</id>    
      <name>central</name>                                                                                                                           
      <url>http://maven.aliyun.com/nexus/content/groups/public</url>   
      <mirrorOf>central</mirrorOf>    
</mirror>