Java version of OpenCvExample. Works as expected.

OpenCvExample.java

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;

public class OtherMain {
    static { System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }

    public static void main(String[] args) {
        Mat m = Mat.eye(3, 3, CvType.CV_8UC1);
        System.out.println("m = " + m.dump());
    }
}