A DESCRIPTION OF THE PROBLEM :
Note: this is actually regarding all Java Releases and OS independent.

Issues at:
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/ClassLoader.html#getResource(java.lang.String)
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Class.html#getResource(java.lang.String)

These methods are lacking explanation regarding their parameter "name" and needs improvement.

1) It should be clearer, that Class#getResource(String) will search relative to the package, unless an absolute path is passed, and for ClassLoader#getResource(String) expects an absolute path.
2) For ClassLoader#getResource(String) should also be noted, that a leading '/' will actually cause problems.

Example:
Absolute resource path: /org/example/resource.res

Accessing the resource via org.ExampleClass:
ExampleClass.class.getResource("example/resource.res"); // works as expected
ExampleClass.class.getResource("/org/example/resource.res"); // works as expected

Accessing the resouce via org.ExampleClass.class.getClassLoader():
ExampleClass.class.getClassLoader().getResource("org/example/resource.res"); // works as expected
ExampleClass.class.getClassLoader().getResource("/org/example/resource.res"); // breaks, unexpected behavior