Java applets: How do games like Runescape preload and save resources so the user doesn't have to download them again later?

Question

The first time a user plays Runescape (which is played via Java applet), the applet takes a few minutes to download a large amount of data. On subsequent plays, this data is retrieved not from the server, but from somewhere on the client's PC.

Where is this data saved to, and how is it done?

Answer 1

Alternatively to signing your applet, you could give your applet a JNLP file , which will give it access to the javax.jnlp package. You can then use DownloadService to do caching of data you download. This will cause Java Web Start to cache your files.

Answer 2

RuneScape uses a signed applet which gives them access to the file system.

If you look in c:\\.jagex_cache_32 or something like that, you'll find the data files.