Class.getResource and ClassLoader.getSystemResource: is there a reason to prefer one to another?

There are several ways to load resources, each with a slightly different meaning -

ClassLoader::getSystemResource() uses the system classloader. This uses the classpath that was used to start the program. If you are in a web container such as tomcat, this will NOT pick up resources from your WAR file.

Class<T>#getResource() prepends the package name of the class to the resource name, and then delegates to its classloader. If your resources are stored in a package hierarchy that mirrors your classes, use this method.

ClassLoader#getResource() delegates to its parent classloader. This will eventually search for the resource all the way upto the system classloader.

If you are confused, just stick to ClassLoader#getResource()

From Class.getResource( )

This method delegates the call to its class loader, after making these changes to the resource name: if the resource name starts with "/", it is unchanged; otherwise, the package name is prepended to the resource name after converting "." to "/". If this object was loaded by the bootstrap loader, the call is delegated to ClassLoader.getSystemResource.

and ClassLoader.getSystemResource( )

Find a resource of the specified name from the search path used to load classes. This method locates the resource through the system class loader