This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
If you have a factory object, you won't ever SEE the call to a constructor...
Sure, the makeSportsCar method probably calls a constructor, or it calls a method that calls a constructor... but if i don't own the autoPlant class, and don't have access to it's source, i won't ever be able to see the constructor.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors