For a list that contains the following classes:
class Bar {}
class Baz extends Bar {}
class SubBaz extends Baz {}
class Foo extends Bar {}
class SubFoo extends Foo {}

List list = new ArrayList();
list.add(Bar.class);
list.add(Foo.class);
list.add(Baz.class);
list.add(SubFoo.class);
list.add(SubBaz.class);
Collections.sort(list, new ClassHierarchyComparator());

output of sorting:
Foo,Baz,SubFoo,SubBaz,Bar

We don' t have subclasses before superclasses.

If we use this as the last line of the comparator:
return c2.getName().compareTo(c1.getName());

output of sorting:
SubFoo,SubBaz,Foo,Baz,Bar,