Add .dll to java.library.path in Eclipse/PyDev Jython project

I'm trying to use a compiled .jar Java library in my PyDev Jython project.

I successfully added the .jar to the PYTHONPATH and was able to begin coding with auto complete working.

The library requires a .dll extension as well, javaHeclib.dll, so I added that to the External Libs section of my project.

I can import the library fine, but I get an error when I try to access any of its functions:

java.lang.UnsatisfiedLinkError: java.lang.UnsatisfiedLinkError: no javaHeclib in java.library.path

I added a VM argument to my Run Configuration, with no luck:

-Djava.library.path="Y:/path/to/javaHeclib.dll;${env_var:PATH}"

I can run the library from the command line just fine using the java.library.path above.

Experimenting in the PyDev Console, I noticed I can load the .dll extension with an absolute path, but not a relative one:

>>> import java.lang
>>> java.lang.System.load('Y:/path/to/javaHeclib.dll')
>>> java.lang.System.loadLibrary('javaHeclib')
Traceback (most recent call last):
  File "<console>", line 1, in ?
java.lang.UnsatisfiedLinkError: java.lang.UnsatisfiedLinkError: no javaHeclib in java.library.path

Unfortunately, the library is using the the System.loadLibrary call above, and I don't have access to its source.

Why is javaHeclib.dll not in my java.library.path?

EDIT

Setting the java.library.path to the directory containing the dll didn't allow me to load it using System.loadLibrary.

-Djava.library.path="Y:/path/to/dll/;${env_var:PATH}"

(Using forward slashes didn't make a difference.) I also tried changing the default VM args in eclipse.ini, with no luck:

-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx384m
-Djava.library.path="Y:\path\to\dll\;${env_var:PATH}"

Solution

I got this working.

For future reference:

Say the dll you need is in Y:\path\to\dlls\lib\. Then set your Run Configuration's working directory to Y:\path\to\dlls\ and set your VM arguments to include -Djava.library.path=lib.

That's it, it should now work. I don't know why specifying an absolute path in java.library.path didn't work previously, but setting a working directory seems to have done it.

Perhaps it's something peculiar to the specific library I'm using (or that Eclipse is running from a different drive than the library is on)...