@Override
public String getTokenStrForm(String tokenSignature) throws IOException {
UserGroupInformation ugi = UserGroupInformation.getCurrentUser();
TokenSelector<? extends TokenIdentifier> tokenSelector = new DelegationTokenSelector23();
Token<? extends TokenIdentifier> token = tokenSelector.selectToken(
tokenSignature == null ? new Text() : new Text(tokenSignature), ugi.getTokens());
return token != null ? token.encodeToUrlString() : null;
}
@Override