Friday, May 06, 2005

Well it's the night before the wedding, and I should be trying to make sure everything is ready. Instead I've finished the first JNI wrapper class for the OS X.4 metadata classes. It hasn't been easy finding the time, as I was trying to work on real Kowari stuff, as well as trying to help Anne with all those last minute details.

The class I've finished is MDItem. This is a direct rip-off of the MDItem class found in the Core Framework. There is a one-to-one correspondence between the classes' methods. There are a couple of minor TODO items, and I should add in a list of the common attributes, but it's basically done.

A lot of work went into the code that converts Core Framework objects into Java objects, and back again. This code will get re-used heavily, so any further work will be a lot faster.

Speaking of further work, the main class I need to work on now is MDQuery. I expect to start on that next week. After I have that one I should be able to start on the resolver! There's also MDSchema, but I don't think it's as important to get things running. I also can't see the need to try and write a file importer in Java, as the file system is not going to want to start up a JVM. :-)

Anyway, if anyone has OS X.4 and is interested in trying it out, then you can find the Xcode project here. The class comes with a main() to test it out, so you can run the resulting jar like this:

  $ cd build
$ java -jar metadata.jar libmetadata.jnilib
The output is in two parts. The first part is all of the attributes, and gives the same results as the mdls command. The second part is a repeat of the first part, but only tries to pick up every second attribute instead (this is to test a different method). You'll note that I ran it on the library itself, but you can run it on any file in the system.

I hope someone likes it. :-)

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