Small Project Backend development

We want to create the back-end for a web-app Βackend functions: The backend is for an e-shop which gives its clients the oppurtunity to choose the products they like and the quantity of each product. The info of the products buyer wants to buy must be writen in a "purchase card". The backend should be able to allow all possible management functions of a purchase card and implementation of the completion of the electronic order (checkout). All the above functions should be supported via a database which should have the appropriate schema for storage and query the required card management information & checkout information. The backend must be implemented in a Jersey-based rest service or any JAX-RS standard and there has to be also a DBMS. More specific instructions when project is accepted.