CODEWITHSUNDEEP
javaswingembedded-resourceimageicon
Muhammad Rifqi
Muhammad Rifqi

Reputation: 21

unable to get the path(url) of image with createIcon() method

So when i'm tried to put an icon to my button with createIcon() method that i declared inside of the button's class, it works fine.

BUT,

when i try to put the method in another class (say Utils.java), so that i don't need to re-declare the method in the class where the object needs icon, i get this message.

Unable to load image: /images/Save16.gif
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException: Cannot invoke "java.net.URL.toExternalForm()" because "location" is null

*there's more message if needed

this is the button's class with createIcon() method inside

public class Toolbar extends JToolBar implements ActionListener{
   private final JButton saveBtn;
   
   public Toolbar() {
      saveBtn = new JButton();

      saveBtn.setIcon(createIcon("/images/Save16.gif"));

      saveBtn.setToolTipText("Save");
      saveBtn.addActionListener(this);
      add(saveBtn);
   }

   private ImageIcon createIcon(String path) { 
      URL url = getClass().getResource(path);
    
      if(url == null) {
         System.err.println("Unable to load image: " + path);
      }
    
      ImageIcon icon = new ImageIcon(url);
    
      return icon;
  }
}

this is the createIcon() method that i'm trying to declare in another class

public class Utils {
    public static ImageIcon createIcon(String path) {
        URL url = System.class.getResource(path);

        if(url == null) {
                System.err.println("Unable to load image: " + path);
        }

        ImageIcon icon = new ImageIcon(url);

        return icon;
    }
}

which changed the setIcon() method into:

saveBtn.setIcon(Utils.createIcon("/images/Save16.gif"));

from what i analyzed in the message the problem is might be the url which can't get the path from my button's class, i've tried several alternatives but it's still didn't work. how should i properly set this up? thanks

Upvotes: 0

Views: 4137

Answers (1)

camickr
camickr

Reputation: 324098

This works:

URL url = getClass().getResource(path);

because you get the class of your Toolbar class, which is where all your other classes/files are located.

This doesn't work:

URL url = System.class.getResource(path);

because the "System" class is found in the JDK not with your application classes.

I would guess you could try:

URL url = Utils.class.getResource(path);

Upvotes: 1

Related Questions