Loading resources like images while running project distributed as JAR archive
Solution 1
First of all, change this line :
image = ImageIO.read(getClass().getClassLoader().getResource("resources/icon.gif"));
to this :
image = ImageIO.read(getClass().getResource("/resources/icon.gif"));
More info, on as to where lies the difference between the two approaches, can be found on this thread - Different ways of loading a Resource
For Eclipse:
For NetBeans:
For IntelliJ IDEA:
- Right-Click the src Folder of the Project. Select New -> Package
- Under New Package Dialog, type name of the package, say resources. Click OK
- Right Click resources package. Select New -> Package
- Under New Package Dialog, type name of the package, say images. Click OK
- Now select the image that you want to add to the project, copy it. Right click resources.images package, inside the IDE, and select Paste
-
Use the last link to check how to access this file now in Java code. Though for this example, one would be using
getClass().getResource("/resources/images/myImage.imageExtension");
Press Shift + F10, to make and run the project. The resources and images folders, will be created automatically inside the out folder.
If you are doing it manually :
- How to add Images to your Project
- How to Use Icons
- A Little extra clarification, as given in this answer's first code example.
QUICK REFERENCE CODE EXAMPLE(though for more detail consider, A little extra clarification link):
package swingtest;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
/**
* Created with IntelliJ IDEA.
* User: Gagandeep Bali
* Date: 7/1/14
* Time: 9:44 AM
* To change this template use File | Settings | File Templates.
*/
public class ImageExample {
private MyPanel contentPane;
private void displayGUI() {
JFrame frame = new JFrame("Image Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
contentPane = new MyPanel();
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private class MyPanel extends JPanel {
private BufferedImage image;
public MyPanel() {
try {
image = ImageIO.read(MyPanel.class.getResource("/resources/images/planetbackground.jpg"));
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
@Override
public Dimension getPreferredSize() {
return image == null ? new Dimension(400, 300): new Dimension(image.getWidth(), image.getHeight());
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this);
}
}
public static void main(String[] args) {
Runnable runnable = new Runnable() {
@Override
public void run() {
new ImageExample().displayGUI();
}
};
EventQueue.invokeLater(runnable);
}
}
Solution 2
There's a much easier way to load and set an image as a frame icon:
frame.setIconImage(
new ImageIcon(getClass().getResource("/resources/icon.gif")).getImage());
And thats all :)! You don't even have to use a try-catch block because ImageIcon
does not throw any declared exceptions. And due to getClass().getResource()
, it works both from file system and from a jar depending how you run your application.
If you need to check whether the image is available, you can check if the URL returned by getResource()
is null
:
URL url = getClass().getResource("/resources/icon.gif");
if (url == null)
System.out.println( "Could not find image!" );
else
frame.setIconImage(new ImageIcon(url).getImage());
Solution 3
The image files must be in the directory resources/
in your JAR, as shown in How to Use Icons and this example for the directory named images/
.
exlux15
Updated on August 26, 2020Comments
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exlux15 over 3 years
I am having a error for my GUI. Trying to set title bar icon then be included in a Runnable JAR.
BufferedImage image = null; try { image = ImageIO.read(getClass().getClassLoader().getResource("resources/icon.gif")); } catch (IOException e) { e.printStackTrace(); } frame.setIconImage(image);
Here is the error I am getting:
Exception in thread "main" java.lang.IllegalArgumentException: input == null! at javax.imageio.ImageIO.read(Unknown Source) at GUI.<init>(GUI.java:39) at GUI.main(GUI.java:351)
The image is in the correct directory which "resources" folder is the root of the project file
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nIcE cOw about 12 years@trashgod : Thankx for the edit, but Better it will be, if you add your edit on top of mine, since the Java Doc explained that in a much better way than, what I did in my answer, it seems like :-)
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trashgod about 12 years@nIcEcOw: Honestly, I think your ASCII art is more legible. :-)
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Andrew Thompson almost 11 years@nIcEcOw This answer was considered worthy of mention in the info. page for embedded-resource. :)
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nIcE cOw almost 11 years@AndrewThompson : Happy to know, that my answer, is providing the knowledge :-) Thankyou. It's a wonderful feeling, to know, that the answer is liked by many :-) Will try to provide more answers with the same valuable inputs, as I did with this answer. Thankyou again and KEEP SMILING :-)
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Lasitha Lakmal over 4 yearswrong... it throws null pointer exception if the image wasn't there
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icza over 4 years@LasithaLakmal What's wrong? Nobody said otherwise. If you need to handle "missing" images, the answer tells to check if
Class.getResource()
returnsnull
. -
clockw0rk over 3 years+1 because ImageIcon will work like a charm in conjunction with bufferedImage ( because they are siblings )