Re: Displaying Images



Sean C. wrote:
Hey, All!

I'm writing a rather complex GUI program using Java 6 and NetBeans IDE
5.5. My project is coming along sharply, but I'm getting hung up on the
simplest of concepts.

I've read the tutorials, looked at the source code to them, searched the
net, read tons of source code and can't seem to make it work in my
project. What I'm talking about is simply displaying a picture on an
element of my forms.

For example, displaying a graphic on my About screen that is related to
the program. Or, showing screenshots that are previews of the various
themes for the Metal look and feel that I have already made.

I've got these images stored under my project source tree in a folder
called resources, but as far as I can tell, the only way these images get
compiled into the resources folder in the JAR are if they are actually
loaded at design time in the IDE.

I don't mind if I have to add these images to the JAR after I've compiled,
if I'm able to load them at runtime. I've tried loading them using a
path-like string, but that doesn't work. I've tried loading them using
getResource() and that doesn't seem to work as well.

I've been pouring over the JavaDocs for the APIs and I'm just getting more
and more confused. I've seen constructors that require an Icon object,
but when I look up that Icon object, it seems to want an Image object for
its constructor. And when I looked up Image, it didn't want a string
either. I've tried building the path using an URL object and can't seem
to get any of this to work.

If someone could please post a code snippet that shows how to load an
image file from the resources folder of the JAR file into a LayeredPane
object (or another object that may work better), I would greatly appreciate
it. It's driving me crazy that the simplest thing (nice-to-have, but *not*
needed) is bogging me down.

Thank you all for your time in reading this very long-winded message. I
hope to hear from some of you in the near future. Have a great day.

Cheers,

Sean

Sorry I don't use NetBeans so I can't help with that.

Use the program below but change the package to suit. Put the image file (kittens.jpg in my case) in a directory called images. You can either add the image directory and files to the jar or not, the loader will get them no matter. Remember that paths are relative to the class being used to load the resource unless you specify / as the first character of the resource name. I like to put my images on JPanels but that's just me. If you compile this and jar it up it should work just fine. If you run it in the directory with the images directory, be cautious that you know which image is being loaded! Change the name of the images directory when you test just to make sure.

package com.knutejohnson.test;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;
import javax.swing.*;

public class test7 extends JPanel {
BufferedImage image;

public test7(String fname) {
URL url = test7.class.getResource(fname);
try {
image = ImageIO.read(url);
setPreferredSize(new Dimension(
image.getWidth(),image.getHeight()));
} catch (IOException ioe) {
ioe.printStackTrace();
}
}

public void paintComponent(Graphics g) {
g.drawImage(image,0,0,null);
}

public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

test7 t7 = new test7("images/kittens.jpg");

f.add(t7,BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
};
EventQueue.invokeLater(r);
}
}

--

Knute Johnson
email s/nospam/knute/
.



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