Java Reference
In-Depth Information
2.1.1. Starting with the architecture
For the purposes of introducing EJB 3, let's focus on a small subset of ActionBazaar func-
tionality in this chapter—starting from bidding on an item and ending with ordering the
item won. This set of application functionality is shown in
figure 2.1
.
Figure 2.1. A chain of representative ActionBazaar functionality used to examine a cross-section of EJB 3. The
bidder bids on a desired item, wins the item, orders it, and instantaneously receives confirmation. Parallel with the
order confirmation, the user is billed for the item. Upon successful receipt of payment, the seller ships the item.
The functionality represented in
figure 2.1
encompasses the essentials of ActionBazaar.
The major functionalities not covered are posting an item for sale, browsing items, and
searching for items. We'll save these pieces of functionality for later. This includes present-
ing the entire domain model, which we'll discuss in
chapter 9
when we start talking about
domain modeling and persistence using JPA 2.
The chain of actions in
figure 2.1
starts with the user deciding to place a bid on an item.
The user, Jenny, spots the perfect Christmas gift for her grandpa and quickly puts down a
starting bid of $5.00. After the timed auction ends, the highest bidder wins the item. Jenny
gets lucky and no one else bids on the item, so she wins it for the grand sum of $5.00. As
the winning bidder, Jenny is allowed to order the item from the seller, Joe. An order in-
cludes all the items you've come to expect from online merchants—shipping information,
billing details, a total bill with calculated shipping and handling costs, and so on. Persuas-
ive Jenny gets her mom to foot the bill with her credit card and has the order shipped direc-
