We dont need these many signatures for this method. How about just have 
public static void loadUnderFs(String tfsAddrRootPath, String ufsAddrRootPath,
      String excludePath) throws IOException {
and
public static void loadUnderFs(TachyonFS tfs, String ufsAddrRootPath,
      PrefixList excludePathPrefix) throws IOException {
?

What do you think?

These many signatures make the testing harder.