cannot load textures

[zlatko]

Hi! I am trying to run a program with textures from a swing tutorial on Painting in Swing and that's what I get:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(ImageIO.java:1378)
at Textures.paintComponent(Textures.java:47)
at javax.swing.JComponent.paint(JComponent.java:1029)
at javax.swing.JComponent.paintChildren(JC... and bla - bla - bla....

Any ideas? Post me for details. Thanks!

[hardwired]

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(ImageIO.java:1378)

This usually means that the class loader could not find the resource it was given so the ImageIO.read method returns null.

In your Painting in Swing article code for Textures:

            URL url1 = ClassLoader.getSystemResource("texture1.png");
            ...
            // Try writing out the url here to see what the class
            // loader came up with
            System.out.println("url1 = " + url1);

            try {
                bimage1 = ImageIO.read(url1);

[zweibieren]

If you are using netbeans,
and if you have placed the textures in the src/ tree,
and if you have NOT done build project,
then you need to do build project
to copy from the src/ tree to the build/ tree.

[zlatko]

to zweibieren: first, thanks! second, I don't use NetBeans. I use a simple text redactor and the terminal to compile and run da progs. thanks anyway.

to hardwired: I guess, that make sense. But the tutorial does not give any .png files to load like you may see here The Puzzle in Java Swing
That means the line

URL url1 = ClassLoader.getSystemResource("texture1.png");

finds this texture.png somewhere in the system (getSystemResourse-Bla-Bla-Bla). I think the .pngs are in the swing's library or what? Sounds stupid. Anyway the println command you adviced gives

Textures.java:45: operator + cannot be applied to java.net.URL

I tried without plus sign, it gives another error.
Last: the point is in the .png files location. Am I right?
Thanks!

[zweibieren]

getSystemResource may be the wrong method

In my project with main class "Tagger", I use

URL imgURL = Tagger.class.getResource(path)

where path is a simple name like foo.png
and foo.png resides in the same directory as Tagger.class.

[zlatko]

foo.png resides in the same directory as Tagger.class.

that's it, there are no .png files included... I knew it from the beginning. It seems like the tutorial is missing them. But: to include a .png file is used as you said:

ImageIcon sid = new ImageIcon(Puzzle.class.getResource("icesid.png"));

but in my case, I work with textures. And I don't know how this line works
to load .png

            
URL url1 = ClassLoader.getSystemResource("texture1.png");

any ideas? see the code Painting in Swing the example "Textures"

[zweibieren]

As I said:

getSystemResource may be the wrong method