IllegalArgumentException while reading an image in java

Question

I am trying to get a image as the icon for a JFrame window, but I got this error while loading the image.

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
    at javax.imageio.ImageIO.read(Unknown Source)
    at quest2.WindowFrame.<init>(WindowFrame.java:21)
    at quest2.WindowFrame.main(WindowFrame.java:39)

This is the code, but I cut out a few lines that do not pertain to this question.

import javax.imageio.ImageIO;  
import javax.swing.ImageIcon;
import javax.swing.JFrame;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class WindowFrame extends JFrame{

    private static BufferedImage BufImage;
    Image image;  //The image for the icon of the frame

    private static final long serialVersionUID = 1L;

    public WindowFrame() {

        //Get a Image for the Icon
            try {
            BufImage = ImageIO.read(getClass().getResource("/src/quest2/Logo.png"));
        } catch (IOException e) {
            e.printStackTrace();
        }

        ImageIcon ii = new ImageIcon(BufImage);
        image = ii.getImage();

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(720, 480);
        setTitle("Quest 2");
        setVisible(true);
        setResizable(false);
        setIconImage(image);
        setLocationRelativeTo(null);
    }

    public static void main(String args[]) {
        new WindowFrame();
    }

}

I'm not sure what I'm doing wrong, so if anyone could give me help with this, that would be great.

Hopefully this [answer](http://stackoverflow.com/a/9866659/1057230), be able to help you somewhat in this direction :-) — nIcE cOw, Jun 27 '14 at 05:04

MadProgrammer · Accepted Answer · 2014-06-27T03:05:48.970

src won't exist at run time...

You should be using...

getClass().getResource("/quest2/Logo.png")

instead

Updated

You should also be catering for the situation where the image may be null, for example...

try {
    BufImage = ImageIO.read(getClass().getResource("/quest2/Logo.png"));
} catch (IOException e) {
    e.printStackTrace();
}

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(false);
setSize(720, 480);
setTitle("Quest 2");
if (BufImage != null) {
    ImageIcon ii = new ImageIcon(BufImage);
    image = ii.getImage();
    setIconImage(image);
}
setLocationRelativeTo(null);
setVisible(true);

Also, changing the resizable state of the frame will affect it's size, you should do this before setting the frames size (preferably using pack) and call setVisible last

You may also want to take a look at Initial Threads and ensure that the UI is initialised within the context of the Event Dispatcing Thread

Also moving the image setting code inside try with a null check for BufImage maybe be a good idea. — Juned Ahsan, Jun 27 '14 at 03:01
@JunedAhsan Or at least deal with the fact that `BufImage` could be `null` at all — MadProgrammer, Jun 27 '14 at 03:02

IllegalArgumentException while reading an image in java

1 Answers1