使用方形图形进行图像裁剪

Question

File originalImage = new File("anyImage.jpg");
BufferedImage newImage = null;

       try{

          newImage = ImageIO.read(originalImage);
          //JPanel np = new JPanel();
          Graphics2D g2 = null;
        //  np.paintComponents(g2);

          g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
          int x = (getWidth() - size.width)/2;
          int y = (getHeight() - size.height)/2;

          g2.drawImage(newImage, x, y, this);
          if(showClip){
          if(clip == null)
          clip = new Rectangle(100,100); // set the size of the rectangle

          clip.x = (newImage.getWidth() - clip.width)/2;
          clip.y = (newImage.getHeight() - clip.height)/2;
          int x0 = (newImage.getWidth() - size.width)/2;
          int y0 = (newImage.getHeight() - size.height)/2;
          if(x < x0 || x + clip.width  > x0 + size.width ||
          y < y0 || y + clip.height > y0 + size.height);
       //  return;
         clip.setLocation(x, y);

         g2.setPaint(Color.RED);
         g2.draw(clip);


    }



       } 

       catch (IOException ex) {
            Logger.getLogger(ImageView.class.getName()).log(Level.SEVERE, null, ex);
        }

我的问题是，我们如何在图像上绘制方形图形，这意味着它应该显示在此代码上，

结果应如下图所示：