I am using SIGAR in a java project with Maven and Spring. I have the Maven Dependency and Maven Repository included in my pom.xml file, as described in this lin
Finally found the solution. I had to download SIGAR from the official source.
Then I had to copy/paste the entire "lib" folder (with all the .so and .dll and whatnot) into the folder "main/src/webapp" of the project, which is used by Spring to store needed apps (or so I assume).
Then after running mvn install, checking the "target" folder and running the newly generated .war file, everything runs as expected.