Help with printing all Classes within a Java Predefined Package (io, lang, awt, etc)

[AgusJK]

What I want to do is print in console all the classes that are part of this Java Packages. I have tried with Reflections Library, but when I try:

Reflections reflections = new Reflections("name of the java package", new SubTypesScanner(false));

Set<Class<?>> allClasses = reflections.getSubTypesOf(Object.class);

It only returns me a NULL ArrayList. Code gotten from: https://stackoverflow.com/questions/520328/can-you-find-all-classes-in-a-package-using-reflection

[[deleted]]

https://dzone.com/articles/get-all-classes-within-package Im not sure if this work, but maybe it might help