"Java.lang.UnsatisfiedLinkError: no opencv_java320 in java.library.path"

Please find below a working snippet. Which you need to adapt to your needs.

assume following file structure

libs\opencv_java320.dll
pom.xml
src\test\java\sub\optimal\OpenCVTest.java

pom.xml - the part for the testing

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.20</version>
            <configuration>
                <argLine>-Djava.library.path=${project.basedir}/libs/</argLine>
            </configuration>
        </plugin>
    </plugins>
</build>

sub\optimal\OpenCVTest.java

package sub.optimal;
import org.junit.Test;
public class OpenCVTest {
    @Test
    public void someOpenCVTest() {
        System.out.printf("java.library.path: %s%n",
                System.getProperty("java.library.path"));
        System.loadLibrary("opencv_java320");
    }    
}

run the test

mvn compile test

output

...
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running sub.optimal.OpenCVTest
java.library.path: X:\develop\opencv-demo/libs/
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: ...
...

This worked for me. I am using intellij on mac

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

public class Test {

 public static void main(String[] args){
    //System.loadLibrary(Core.NATIVE_LIBRARY_NAME); - REMOVE THIS
    nu.pattern.OpenCV.loadShared(); //add this
    Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
    System.out.println("mat = " + mat.dump());
 }
}

And dependency

<dependency>
   <groupId>org.openpnp</groupId>
   <artifactId>opencv</artifactId>
   <version>3.2.0-0</version>
</dependency>

If you are using STS/Eclipse or any IDE then follow the steps to getting solve your unsatisfiedlinkerror-no-opencv-java320 error.

Window -> Preferences -> User Libraries -> New -> create new Library Like attached Image

Note:- Jar location and Native Library Location (opencv/build/java/x64) should be exactly like this while creating the new library.