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I want to set icon to my JFrame. I do the following:

Image icon = Toolkit.getDefaultToolkit().getImage("src/images/icon.jpg");
this.setIconImage(icon);

It works fine when I run this code from netbeans, but when I try to run this code from jar file, images are not shown in my JFrame. I have tried to load images as resources:

this.setIconImage(Toolkit.getDefaultToolkit().getImage(getClass().getResource("/src/images/icon.jpg")));

but when I run this code it fails with NullPointerException

 Uncaught error fetching image:
java.lang.NullPointerException
        at sun.awt.image.URLImageSource.getConnection(URLImageSource.java:99)
        at sun.awt.image.URLImageSource.getDecoder(URLImageSource.java:113)
        at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:240)
        at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172)
        at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)

How can I do this work?

edit: Thanks to all, the problem was solved by specifying image as

Toolkit.getDefaultToolkit().getImage(getClass().getClassLoader().getResource("images/icon.JPG"))

As for it seems rather weird, and would be better if it was like

this.setIconImage(new ImageIcon(pathToIcon).getImage());
maks
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8 Answers8

4

Assuming your JAR file has a top level directory called images, you can use either:

  1. getClass().getResource("/images/icon.jpg") or
  2. getClass().getClassLoader().getResource("images/icon.jpg")
Sanjay T. Sharma
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3

Looking at the source code of URLImageSource, it appears that the reason that getConnection throws an NPE is that it has a null for the url. And that leads me to suspect that 

getClass().getResource("/src/images/icon.jpg")

is returning null. It would do that if it could not locate a resource with that pathname.

I bet that the problem is that you've got the path wrong.

To prove / disprove this, you should run jar tvf on the JAR file, and look for the line that matches "icon.jpg". Is the corresponding pathname the same as what you are using? If not, use the pathname from the matching line in the getResource call and it should work. Alternatively, if the file doesn't show up at all, look at the NetBeans build configs that tell it what to put in the JAR file. (I'm not a NetBeans user, so I can't say where you would need to look ...)

If that leads you absolutely nowhere, another possibility is that getClass().getResource(...) is using a classloader that doesn't know about the JAR file containing the image. (This seems pretty improbable to me ...)

Stephen C
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    jar tvf shows that icon.jpg is located in images/icon.jpg, but neither getClass().getResource("/images/icon.jpg") nor getClass().getResource("images/icon.jpg") doesn't work. But getClass().getClassLoader().getResource("images/icon.jpg") works fine. – maks Mar 30 '11 at 14:45
  • I Have the same problem, but I am doing it inside of a main method, so "getClass()" doesn't work. what should I put instead of that? I tried creating a new instance of the main class, but that gave me an Exception when I tried it. – Ephraim Jul 24 '11 at 20:33
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    Try `YourMainClass.class.getClassLoader().getResource(resourePath)`. – Stephen C Jul 24 '11 at 22:07
2

getResource() loads a resource from classpath, not an OS path, and the after compilation your classpath will not include the /src folder, but rather just its contents. So you'd better try /images/icon.jpg.

Also you may find this discussion somewhat useful.

Community
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Konstantin Burov
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0

You can simply create a package inside the main source, and incluse your images in this package. Then, just call the images in your main class like:

ImageIcon a = new ImageIcon(MainClass.class.getResource("/Package/Image.jpg"));

Gabriel Ozzy
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JFrame f = new JFrame("Edit Configure File");
//Image image = ImageIO.read(getClass().getResource("images/ctx.Icon"));
f.setIconImage(new ImageIcon("images/ctx.PNG").getImage());//this works for me finally
//f.setIconImage(image);
//f.setIconImage(Toolkit.getDefaultToolkit().getImage(getClass().getResource("images/ctx.PNG")));
djv
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Peter Moh
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This should do it assuming you can import javax.imageio.ImageIO:

Image icon = ImageIO.read(this.getClass().getResource("/src/images/icon.jpg"));
this.setIconImage(icon);
jberg
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  • It can not find such file in specified location, but it is there – maks Mar 30 '11 at 10:43
  • hmm..Can you try moving the image file to a folder outside, but at the same level as the src directory. Like: "/resources/images/icon.jpg"? – jberg Mar 30 '11 at 10:53
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.."/src/images/icon.jpg"..

The '/src' prefix of the address seems suspicious. Many apps. will provide separate 'src' and 'build' directories, but it normally ends up that the 'src' prefix is not used in the resulting Jar. I recommend trying.. 

.."/images/icon.jpg"..

& also triple checking that the image is in the location of the Jar that the code is expecting to find it.

Andrew Thompson
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0

For this to work, you should access the images from a directory relative to some fixed class. For example, if the image files are saved in a directory "images" on the same level as the Toolkit.class, then

this.setIconImage(Toolkit.getDefaultToolkit().getImage(Toolkit.class.getResource("images/icon.jpg"))); should work.

Dipmedeep
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