code: public static final void setOwner(String name, Path... files) throws IOException
      {
          if (supports("posix"))
          {
              for (Path file : files)
              {
                  FileSystem fs = file.getFileSystem();
                  UserPrincipalLookupService upls = fs.getUserPrincipalLookupService();
                  UserPrincipal user = upls.lookupPrincipalByName(name);
                  Files.setOwner(file, user);
              }
          }
          else
          {
              JavaLogging.getLogger(PosixHelp.class).warning("no owner support. setOwner(%s)", name);
          }
      }
docs: Change user of given files. Works only in linux.
  @param name
  @param files
  @throws IOException
  @see java.nio.file.Files#setOwner(java.nio.file.Path, java.nio.file.attribute.UserPrincipal)