The company I work for has recently released a java e-commerce product - MerchantSpace.
It can be found at http://www.merchantspace.com

Check it out - there are very few non-enterprise java shopping cart or java
catalog applications available (especially J2EE compliant), so it may be
able to meet your needs.

It is specifically targetted towards java developers and system integrators
who need J2EE compliance and legacy integration capabilities.