如何放置JFrame图标

Question

I want to set an icon for my application in Java. I'm using Eclipse.

I don't know if the way of storing the icon (and the config file by the way) into the project is the best one (I accept suggestions to learn the best way).

Anyway I'm trying to use this line into my extended JFrame class:

setIconImage(Toolkit.getDefaultToolkit().getImage("img/icon.png"));

But doesn't work: still with the coffee cup icon.

How can I access to the icon into package estacionBase.img? Is there a better place to store it? How would I access it then?

Answer 1

Instead of saving your resources alongside your source files, save it outside src in a folder called something like res . It's a good idea to separate your source from your resources.

As for the icon, use setIconImage(ImageIO.read("res/icon.png"));

However:

If your icons are inside a jar , you'll have to use ImageIO.read(Classname.class.getResource("res/icon.png"));

I think that's right, however take care with your relative paths and if it's not working, the first thing to check would the your paths relative to where it's being executed from (whether that's from the .class dirs or from a jar at some stage).

Answer 2

For the saving issue: Create a new source folder in your project and call it res or so. Then you can put your ressources in there. As res is marked as a source folder, it will be in your jar as well.

For the loading, you can use

setIconImage(ImageIO.read("res/icon.png"));

or

setIconImage(
    new ImageIcon(getClass().getResource("res/icon.png"), description).getImage()
);

Of course, it is also ok to have the images in between your source code. Most of the official Java demo's (for instance here ) do it that way. It's more compact. I wouldn't use that technique for larger projects though. It can get quite messy.

Answer 3

Try to put your image into a second folder such as /res as other people suggested then use the code:

setIconImage(Toolkit.getDefaultToolkit().getImage(getClass().getResource("path/to/icon.png")));
I tried this for my applications and it worked every time. Also, try not to put the image into a package as well.