getResource error when starting application in a jar file

[Steve O Murphy]

I have an application which I've packaged into a jar file. One of the first statements in my app is

String rootResource = this.getClass().getResource("/").getPath();

However, when I run my app, I get a null pointer exception from the above line of code. When I run the app from within Eclipse, the app starts fine.

This is my first time creating a jar file and I suspect my error has something to do with that. Can anyone provide clues/suggestions as to what might be wrong?

Thanks.

[Sai Hegde]

This is because class loading in eclipse works a little differently than elsewise. Try this --

this.getClass().getProtectionDomain().getCodeSource().getLocation().toURI().getPath();

[Steve O Murphy]

Thanks Sai. That solved the problem.

When I print the value of the rootResource to the console I get:

/D:/D_LocalWork/APIReferenceCompares-jar/ApiRefereceCompares.jar

That is indeed the path/name of the jar file.

From there I need to get to the "images" directory in the jar file so I can load images into the app's user interface.

The "images" directory is in the root of the jar file. I'm using the following:

String imagesDirectory = rootResource.concat("/images");

Is that the correct way to get the path to the images directory?

When I try loading an icon, I get an error. Here is what I use:

String appIconString = "Spark_32.GIF";
BufferedImage appIcon = null;

try 
{
	appIcon = ImageIO.read(new File(imagesDirectory.concat("\\").concat(appIconString)) );
	} catch (IllegalArgumentException e) {
			MsgBox.msgErr("Unable to find application icon (" + appIconString +")");
	} catch (IOException e) {
			MsgBox.msgErr("Unable to load application icon (" + appIconString +")");
}

I get the second exception.
The code for loading the icon works in Eclipse.

Thanks for bearing with me!
Steve

[Sai Hegde]

Are the images bundled within the jar or will they be picked up from the location of your JAR file?

[Steve O Murphy]

The images are in the jar file, in a directory within the jar file called "images"

Thanks.

[Sai Hegde]

Try it this way --

URL url = this.getClass().getResource("images/spark32.gif"); 
Image img = Toolkit.getDefaultToolkit().getImage(url);