What are the different methods of developing an online shopping cart?

Answer 1

Enterprise Java Beans are a good solution for this problem, if you're willing to invest the time in learning it.

Answer 2

1. Don't reinvent the wheel if you don't have to........download one of the many already built shopping carts, like ZenCart or others. See how each one would fit your needs and just use it........

You can go through all the hassles of new development, but WHY? Unless there is a need that isn't being met by any of the freely available one.....but then, the open source solutions are meant to be modified/customized.