I get files from friend who don't use netbeans IDE, when i open file that contain special caracter like 'é','à',... it show me this popup message :
if i say yes it open the file and changes those caracters to '�' like or
Any idea how to open the file safely?
The letters you are mentioning seem to be French. You need to open the file, specifying the original encoding, then save the file as UTF-8