public final class MyClass {
	private final String foo;
	
	public MyClass(@NonNull String bar) {
		foo = bar;
	}
	
 	public final @NonNull String getFoo() {
		return foo;
	}
}

Any final field that is directly initialized to a value that is statically known to be non-null is considered as effectively non-null, even if no @NonNull annotation is attached.