JavaCV with java.lang.UnsatisfiedLinkError - javacv

Question

The code is very simple, just open a picture.
But when I run this I have an error like this:
Exception in thread "main" java.lang.UnsatisfiedLinkError: org.opencv.imgcodecs.Imgcodecs.imread_1(Ljava/lang/String;)J
at org.opencv.imgcodecs.Imgcodecs.imread_1(Native Method)
at org.opencv.imgcodecs.Imgcodecs.imread(Imgcodecs.java:112)
According to the searched solution, I add this System.load(Core.NATIVE_LIBRARY_NAME) to the main(), doesn't work:
Exception in thread "main" java.lang.UnsatisfiedLinkError: Expecting an absolute path of the library: opencv_java401
at java.lang.Runtime.load0(Runtime.java:806)
at java.lang.System.load(System.java:1086)
Or this System.loadLibrary(Core.NATIVE_LIBRARY_NAME), still not work:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no opencv_java401 in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1122)
My project is build by gradle, the dependencies is (official doc):
compile group: 'org.bytedeco', name: 'javacv-platform', version: '1.5'
Thank you for your help.

Answer 1

Self answer.
My import is wrong. It should be
import static org.bytedeco.opencv.global.opencv_imgcodecs.imread
instead of
import static org.opencv.imgcodecs.Imgcodecs.imread
This error caused the wrong package to be used.
The correct code is:
import org.bytedeco.opencv.opencv_core.Mat;
import static org.bytedeco.opencv.global.opencv_imgcodecs.imread;
public class DemoApplication {
public static void main(String[] args) {
Mat image = imread("/root/test.png");
System.out.println("width：" + image.cols());
System.out.println("height：" + image.rows());
}
}