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Hi, i'm trying to create an application, it will detect our face through a webcam, i'm referring to this tutorial and write it in java code. here is my code:

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfRect;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Size;
import org.opencv.core.Scalar;
import org.opencv.highgui.Highgui;
import org.opencv.highgui.VideoCapture;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.CascadeClassifier;


/**
 * @author Lycosa
 *
 */
public class detedctAndDisplay {



    /** Global variables */
     private static String face_cascade_name = "haarcascade_frontalface_alt.xml";
     private static String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
     private static CascadeClassifier face_cascade = new CascadeClassifier();
     private static CascadeClassifier eyes_cascade = new CascadeClassifier();
     private static String window_name = "Capture - Face detection";


     public static void detectAndDisplay(Mat frame)
     {
       Mat frame_gray = new Mat();
       MatOfRect faces = new MatOfRect();

       Rect[] facesArray = faces.toArray();

       Imgproc.cvtColor(frame, frame_gray, Imgproc.COLOR_BGRA2GRAY);
       Imgproc.equalizeHist(frame_gray, frame_gray);

       //-- Detect faces
       face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0, new Size(30, 30), new Size() );

       for (int i = 0; i < facesArray.length; i++)
       {
         Point center = new Point(facesArray[i].x + facesArray[i].width * 0.5, facesArray[i].y + facesArray[i].height * 0.5);
         Core.ellipse(frame, center, new Size(facesArray[i].width * 0.5, facesArray[i].height * 0.5), 0, 0, 360, new Scalar(255, 0, 255), 4, 8, 0);

         Mat faceROI = frame_gray.submat(facesArray[i]);
         MatOfRect eyes = new MatOfRect();

         Rect[] eyesArray = eyes.toArray();

         //-- In each face, detect eyes
         eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0,new Size(30, 30), new Size());

         for (int j = 0; j < eyesArray.length; j++)
         {
            Point center1 = new Point(facesArray[i].x + eyesArray[i].x + eyesArray[i].width * 0.5, facesArray[i].y + eyesArray[i].y + eyesArray[i].height * 0.5);
            int radius = (int) Math.round((eyesArray[i].width + eyesArray[i].height) * 0.25);
            Core.circle(frame, center1, radius, new Scalar(255, 0, 0), 4, 8, 0);
         }
       }
       //-- Show what you got
       Highgui.imwrite(window_name, frame);
     }

    /**
     * @param args
     */
     public static void Main(String args[])
     {
       VideoCapture capture;
       Mat frame = new Mat();

       //-- 1. Load the cascades
       if (!face_cascade.load(face_cascade_name))
       {
           System.out.print("--(!)Error loading\n");
           return;
       }
       if (!eyes_cascade.load(eyes_cascade_name))
       {
           System.out.print("--(!)Error loading\n");
           return;
       }

       //-- 2. Read the video stream
       capture = new VideoCapture(0);
       if(!capture.isOpened())
       {
           System.out.println("Did not connect to camera.");
       }
       else
       {
           capture.retrieve(frame);
           detectAndDisplay(frame);
           capture.release();
       }
       }
}

There are no error in the code, but i'm not sure whether i'm doing it correctly because when i'm trying to run the app it says "Selection does not contain main type". What is that mean?