code: @Override
      public void transferInitiated(TransferEvent event) {
          TransferResource resource = event.getResource();
  
          StringBuilder sb = new StringBuilder()
              .append(event.getRequestType() == TransferEvent.RequestType.PUT ? "Uploading" : "Downloading").append(":")
              .append(resource.getRepositoryUrl()).append(resource.getResourceName());
  
          downloads.put(resource, new Long(0));
          log.fine(sb.toString());
      }
docs: /*
  (non-Javadoc)
  
  @see org.sonatype.aether.util.listener.AbstractTransferListener#transferInitiated
  (org.sonatype.aether.transfer.TransferEvent)