[TYPO3-dev] Import Extension add media files

[DirkHo]

Hello,

I'm developing a content importer for data from my old website to use it 
in typo3. Therefore I wanted to upload related files (PDFs, GIFs, JPEGs, 
e.g.).

Could you please give me a hint, which classes to use from Typo3 to 
upload these files to Typo3 and add them as media file to the related 
content element?

Thanks and best wishes,

Dirk