UpgradeUtil.getConceptIdForUnits does not ensure that the FileInputStream it creates is closed in case of an exception.
Use the try-with-resource statement
to ensure FileInputStream will be closed in any case.
This issue is also reported by the sonar qube at
Furthermore, I suggest to use the try-with-resource on the PreparedStatement
which are used multiple times in this class, such as
This makes the code more concise (the final block with the select.close() could be removed).