if you want to load your image or file in the resources folder, you might need to use BufferedImage and ImageIO :

import javax.swing.ImageIcon;
import javax.swing.JFrame ;
import javax.swing.JPanel ;
import javax.imageio.ImageIO ;
import javax.swing.SwingUtilities;
import java.awt.Graphics;
import java.awt.Graphics2D ;
import java.awt.Image;
import java.awt.image.BufferedImage ;
import java.awt.Dimension ;
import java.io.IOException;

public class LoadImage extends JFrame {
    public LoadImage() {
        super("Title") ;
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ;
        
        add(new Panel()) ;
        // use this idea if you want to have exact window location
        pack() ;
        setLocationRelativeTo(null) ; // makes it center
    }
    
    // If you want to run the image in your panel
    public static class Panel extends JPanel {
        BufferedImage bufferedImage ;
        ImageIcon imageIcon ;
        Image image ;
        public Panel() {
            setLayout(null) ;
            setPreferredSize(new Dimension(600, 600)) ;
            
            // for loading your resources inside of you program, for example: src/main/resources/path/to/your/location.png
            try {
                bufferedImage = ImageIO.read(getClass().getResourceAsStream("/path/to/your/location.png"));
            } catch (IOException e) {
                e.printStackTrace() ;
            }
            
            // for loading your image outside the program, for example: saves/image.png
            // if you create your jar, you need to put your files outside the jar
            image = new ImageIcon("path/to/your/location.png").getImage() ;
            imageIcon = new ImageIcon("path/to/your/location.png") ;
        }
        
        @Override 
        public void paintComponent(Graphics g) {
            Graphics2D g2d = (Graphics2D) g ;
            super.paintComponent(g) ;
            // for buffered image 
            if (bufferedImage != null) {
                g2d.drawImage(bufferedImage, 0, 0, null) ;
                g.drawImage(bufferedImage, 0, 0, null) ;
            }
            //for image icon 
            if (imageIcon != null) {
                g2d.drawImage(imageIcon.getImage(), 0, 0, null) ;
                g.drawImage(imageIcon.getImage(), 0, 0, null) ;
            }
            // for image 
            if (image != null) {
                g2d.drawImage(image, 0, 0, null) ;
                g.drawImage(image, 0, 0, null) ;
            }
        }
    }
    
    public static void main(String[] args) {
        // makes it write all the codes, then shows the code
        SwingUtilities.invokeLater(() -> new LoadImage().setVisible(true)) ;
    }
}

hope this solution help you :) i created a library that can handle your images, wav musics, files, creating or loading saves from various locations, user home, program directory check the link if you want JStreamLoader library on GitHub