Unit V Enterprise Applications 9
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layer is completely independent and distinct.
clients and servers are very loosely coupled. You need infrastructure to accommodate messaging.
SOA and Web Services
demands or when they are required to support new customers and their IT systems.
(enterprise beans) can perform any of the following tasks:
interface. This scenario is shown in Figure 1.4.
operational solution. The system administrator is responsible for the upkeep and monitoring of
J2EE stack consists of the following:
EJB is the cornerstone for J2EE and uses several other J2EE technologies.
better suited to handling simple request/response needs, and they do not require sophisticated
lookup in a service-oriented architecture as supported by Web Services technologies.
}
archive’s META-INF directory. Your specific J2EE product may
functionally equivalent. Actually, there is a third option that relies on a dynamic invocation
// Call the hello() method
This is shown in Figure 6.1.
significant.
¦¦ Persistable, so that it can be saved back into storage again, thus updating the database data
instances needs to be refreshed depending on the current transactional state (see Chapter 12).
method should
method after activation. This is shown in Figure 6.5.
. In this case, you
identify the bean.
public javax.ejb.EJBLocalObject getEJBLocalObject();
took a look at entity contexts.
load old entity bean data.
details the class diagram for our bank account.
* @throw AccountException thrown if amount > available balance
, shown in Source 7.5.
. We
/**
primary keys.
* Deposits amt into account.
Connection conn = null;
}
*/
try {
* 2) Store account in DB
}
}
try {
performance.
Iterator i = home.findByOwnerName( “John Smith”).iterator();
}
Passivate Your Bean:
synchronization.