for this program, i successfully did create an output.txt, but i have some weird characters in front of "hello" when i open it in notepad or wordpad.
this is probably because i'm using a japanese computer.
how can i fix this?
ObjectOutputStream does not do what you think it does (read its javadocs for more details on what it does). If you want a plain text file, use the BufferedOutputStream directly (or wrap a BufferedWriter around a FileWriter).