An update will break any worries, the course of the lines of file continu and database recording is effective.
However when it comes to inserting a new object I get an error : " org.springframework.dao.DuplicateKeyException: a different object with the same identifier value was already associated with the session: [fen.NuisanceType#2202]; nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session"
The registration of the object in question is effective , but the error raised off the path of the file.
When i uncommented the "try and catch" I bypasses the error and so all my copies of each file are created in the database .
I thus found a way around my worries, but I do not find it very clean and i come to you to try to understand my problem.