Question

this is basic example I got for a GUI from a book called Java In Easy Steps, I implemented the code as per the example but the imagery does not appear. What do I need to do in order to make it appear, is because of the URL getClassLoader?

Ideally I would like to be able to save a file to my workspace and use that file as a part of the GUI.

import javax.swing.*;

class Buttons extends JFrame {

    JPanel pnl = new JPanel();
    ImageIcon tick = new ImageIcon("tickURL");
    ImageIcon cross = new ImageIcon("crossURL");

    JButton btn = new JButton("Click Me");
    JButton tickBtn = new JButton(tick);
    JButton crossBtn = new JButton("STOP", cross);

    ClassLoader ldr = this.getClass().getClassLoader();
    java.net.URL tickURL = ldr.getResource("tick.png");
    java.net.URL crossURL = ldr.getResource("cross.png");

    public Buttons(){

        super("Swing Window");
        setSize( 500, 200);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        add(pnl);
        setVisible(true);

        pnl.add(btn);
        pnl.add(tickBtn);
        pnl.add(crossBtn);

    }

    public static void main(String[]Args){

        Buttons gui = new Buttons();

    }

}

Answer 1

ClassLoader ldr = this.getClass().getClassLoader();
java.net.URL tickURL = ldr.getResource("tick.png");
java.net.URL crossURL = ldr.getResource("cross.png");

JPanel pnl = new JPanel();
ImageIcon tick = new ImageIcon(tickURL);     // <-- a URL is needed here, not a string
ImageIcon cross = new ImageIcon(crossURL);   // same here

JButton btn = new JButton("Click Me");
JButton tickBtn = new JButton(tick);
JButton crossBtn = new JButton("STOP", cross);

1. load your assets with the classLoader (if they are in your classpath),
2. create your icons with these assets,
3. create your buttons with these icons

As simple as that.