Re: Resource confusion
On Mon, 30 Jan 2012 13:33:30 -0800, Roedy Green wrote:
On Sat, 28 Jan 2012 17:47:48 +0000 (UTC), Novice <novice@example..com>
wrote, quoted or indirectly quoted someone who said :
I'm having trouble figuring out the best way of obtaining existing files
for my program to use.
I would put the read-only config files in a resource in a jar. This
means they can't get lost and they work even if the user is not capable
of configuring his own files. They are also compact. They get updated
automatically when you update the program.
You problem then becomes, where to put the user's files. JNLP lets you
allocate some space with a hideous name, not really suitable for the
user to insert things except via your game. If he creates them with a
text editor you might import them into that space or store the filenames
(not files) in your own space so he can pick them off a menu by
unqualified name, and you then go fetch them from the original locations
as needed.
Same here: I'd put the defaults in the jar and, allow the user to put
overriding files in a master location and a one local to the user: if it
was a UNIX type system the master location would be /usr/local/etc and
the local location would be the hidden directory ~/.myapp and the program
would use a search something like this;
List<String> config = new List<String>();
config.add("~/.myapp/config.txt");
config.add("/usr/local/etc/config.txt");
boolean found = false;
for (String s : config)
{
File cf = new File(s);
if (cf.exists())
{
found = true;
// use the configuration in cf
}
}
if (!found)
// use the default configuration held as a resource in the jar file
which lets the user's configuration take preference over the site
configuration in /usr/local/etc, which in turn takes precedence over the
jar file resource.
NOTE: this assumes that each configuration is complete.
Another way to do it is to read all three config files in the *reverse*
order (from jar file, then /usr/local/etc and finally from ~/.myapp) with
items read from an earlier file being overwritten by matching items from
a later file. This approach means that the config in the jar file must
give a default value for every item, but the site and user configurations
only need to provide values for items they want to customise.
--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |