I am having an issue with an address book because whenever you add a contact then shut the program. The file it is stored in, clears its contents. The objects are written in the file worker class and I think the issue is probably in the FileWorker class. It is written in netbeans so yeah. The link to it is
http://pastebin.com/Mw4c7kFb

You either need to read the file first, or open the file in read/write. new FileOutputStream by default will clear the file it is opening for writing.

Also, you are doing this in a terribly bad way. Rewriting the entire file every time you add a contact is a huge waste of time. File IO is *slloooowww*.

Either:
1) Stream the output to the file (eg, adding one contact writes one contact to the still open output stream)
Or
2) Keep the entire contact list in memory until a save() is called, at which point the in memory data is written to the file

Hey Mr. Spambot

bye Mr. Spambot (soon..)