Preparing JNA for use in Eclipse

Question

Background: I'm doing machine learning research, and want to use the FANN library to construct neural networks. The source code is written in C, but I need it wrapped so that I can use it with a lot of Java classes we've created.

Question: The website provides a link to an already well received wrapper software called fannj. Its dependencies is the FANN library source code and JNA. I've never done wrapping before so JNA is brand new to me. The github homepage for the code mentions " you must set the jna.library.path system property to the path of the FANN Library" . I'm currently in the process of trying to do this in Eclipse on Mac OS X. A friend of mine mentioned to me earlier that it means I have to pass the location of the FANN library as argument to the virtual machine, but he only showed me how to do this via the shell. I never actually ran this command from the shell, because I wasn't sure how it would conflict with whatever configurations I do in Eclipse later.

How do I set the jna.library.path in Eclipse? The JNA directory is huge, and I don't know where the actual executable is. My friend suggested I modify its run configuration through use of the argument tab, but like I said I don't actually know where the executable is. All I have is the large uncompressed jar file. How can I go about getting it set up in Eclipse?

Answer 1

You don't set in an IDE, just insert in some piece of code that is called BEFORE JNA is called, something like this:

  System.setProperty("jna.library.path", "path you need"); 

Where System is java.lang.System . As for what path you need it must be the path that contains compiled dynamically linked FAAN library (a *dll).

Or just forget that alltogether and dump FAAN (*dlls, *so..) into Windows/system32 (or other appropriate folder on system you use) and these dll's will be on default search path.

Answer 2

Two allow Eclipse to use JNA, all you need to do is to put two jar files in Eclipse's Java Build Path, jna.jar and platform.jar. That's it.

To do this for an individual project, right click on the project in the Package Explorer, click Properties (at the bottom), click Java Build Path on the left, then the Add External Jar files. Browse to the directory with your JNA files and add those two files.