Accessing JAR resources

Question

I have a jar file with resources (mainly configuration for caches, logging, etc) that I want to distribute.

I'm having a problem with the relative paths for those resources, so I did what I've found in another stackoverflow question, which said that this was a valid way:

ClassInTheSamePackageOfTheResource.class.getResourceAsStream('resource.xml');

Sadly this does not work.

Any ideas? Thanks!

PS: Obviously I cannot use absolute paths, and I'd like to avoid environment variables if possible

Answer 1

I always have to puzzle through getResourceAsStream to make this work. If "resource.xml" is in org/pablo/opus, I think you want this:

Name.class.getResourceAsStream("org.pablo.opus.resource.xml");

Answer 2

where the resource.xml found? If in the root of the source tree, try to prefix it with /.

Answer 3

I usually store files and other resources and then retrieve them as URLs:

URL url = MyClass.class.getResource("/design/someResource.png");

Within a static context, or otherwise:

URL url = getClass().getResource("/design/someResource.png");

From an instance.

The above snippets assume that design is a top level folder within the jar. In general, if the path begins with a "/" it assumes an absolute path, otherwise it's relative from the class location.

Answer 4

Make sure that your resource folder is listed as a source folder in your project settings. Also, make sure that the resource folder is set to export when you build your jar.

You can add a .zip extension to your jar file then open it up to ensure that your resources are included and at the expected location.

I always use absolute paths like this:

InputStream input = this.getClass().getResourceAsStream("/image.gif");

When you use absolute paths, "/" is the root folder in the jar file, not the root folder of the host machine.