Database transactions and concurrency - POJOs in Action: Developing Enterprise Applications with Lightweight Frameworks - page 463

Scheduler

Transaction Interceptor

<<interface>>
RestaurantNotification
TransactionScripts

RestaurantNotification
TransactionScriptsImpl

sendOrders()

void sendOrders()

<<interface>>
RestaurantNotification
Gateway

<<interface>>
OrderDAO

Order.xml

sendOrder()

findOrdersToSend()
markOrdersAsSent()

<sqlMap>

<select
name="findOrdersToSend" ... >
SELECT ...
</select>

OrderDAOIBatisImpl

OrderDTO

<update
name="markOrdersAsSent" ... >
UPDATE ...
</update>

findOrdersToSend()
markOrdersAsSent()

...
</sqlMap>

SqlMapClient
Template

queryForList()
update()

Figure 12.3 Transaction script-based design for the Send Orders to Restaurant use case

SQL statements that are executed by the OrderDAO and the configuration of the
Spring TransactionInterceptor or JDBC DataSource .
The key classes in the design are:
■ RestaurantNotificationTransactionScripts , which implements the transac-
tion script
■ Scheduler , which periodically invokes the RestaurantNotificationTransac-
tionScripts