question: public synchronized void deleteFile ( Reference < ? > ref , String fileName ) { if ( ref != null ) { String f2 = refMap . remove ( ref ) ; if ( f2 != null ) { if ( SysProperties . CHECK ) { if ( fileName != null && ! f2 . equals ( fileName ) ) { DbException . throwInternalError ( "f2:" + f2 + " f:" + fileName ) ; } } fileName = f2 ; } } if ( fileName != null && FileUtils . exists ( fileName ) ) { try { IOUtils . trace ( "TempFileDeleter.deleteFile" , fileName , null ) ; FileUtils . tryDelete ( fileName ) ; } catch ( Exception e ) { } } }
target:  Delete the given file now. This will remove the reference from the list.