I'm currently developing a desktop application in java, which stores user data such as bookmarks for ftp-servers. When deciding how to save these informations, I ended up using xml, simply because I like the way xpath works. I was thinking about json too, which seems more lightweight.

What is your preferred way to store data in java desktop applications (in general) and why? What about java-persistence, does that have any advantages worth noting? And how much does the size of user data matter? Its not always possible to store data in a database (or preferable), and in my experience xml does not scale well. Let me know what you think!