当我运行下面的代码时，我得到了下面的错误，但它以前工作过，我不确定Eclipse得到了什么，而且不再是好的

错误：无法初始化主类src.convolution原因：java.lang.NoClassDefFoundError:组织/开放性/核心/材料

package src;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

public class convolution {
   public static void main( String[] args ) {

      try {
         int kernelSize = 9;
         System.loadLibrary( Core.NATIVE_LIBRARY_NAME );

         Mat source = Imgcodecs.imread("C:/Users/B & B/Desktop/ProcIMG/grayscale.jpg", Imgcodecs.IMREAD_GRAYSCALE);
         Mat destination = new Mat(source.rows(),source.cols(),source.type());

         Mat kernel = new Mat(kernelSize,kernelSize, CvType.CV_32F){
            {
               put(0,0,-3);
               put(0,1,-3);
               put(0,2,-3);

               put(1,0-3);
               put(1,1,0);
               put(1,2,-3);

               put(2,0,5);
               put(2,1,5);
               put(2,2,5);
            }
         };       

         Imgproc.filter2D(source, destination, -1, kernel);
         Imgcodecs.imwrite("C:/Users/B & B/Desktop/ProcIMG/output.jpg", destination);

      } catch (Exception e) {
         System.out.println("Error: " + e.getMessage());
      }
   }
}