Get imports for program

Hi All,
My goal is know how are "imports"
at the top of a program discovered/obtained?
I can create a doc folder with my IDE.
TIA
bH

Given this demo program with no imports:

/**
 *This class demonstrates how to load an Image from
 * an external file
 */

@SuppressWarnings("serial")
public class LoadImageApp extends Component {
    BufferedImage img;
    public void paint(Graphics g) {
        g.drawImage(img, 0, 0, null);
    }
    public LoadImageApp() {
       try {
           img = ImageIO.read(new File(
"image/GridImage.jpg"));
       } catch (IOException e) {
       }
    }

    public Dimension getPreferredSize() {
        if (img == null) {
             return new Dimension(100,100);
        } else {
           return new Dimension(img.getWidth(null),
img.getHeight(null));
       }
    }
    public static void main(String[] args) {
        JFrame f = new JFrame("Load Image Sample");
        f.addWindowListener(new WindowAdapter(){
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });
        f.add(new LoadImageApp());
        f.pack();
        f.setVisible(true);
    }
}