Java Reference
In-Depth Information
Second, the embeddable
EJBContainer
object is required to support the EJB Lite group
of the EJB API. EJB API groups will be discussed further in the next section.
1.6.7. EJB API groups
Because EJB technology is the backbone of Enterprise Java development, EJBs need to be
able to provide a large number of services to fulfill business needs. These services include
but aren't limited to transactions, security, remote access, synchronous and asynchronous
execution, and state tracking, and the list goes on. Not all Enterprise solutions require all
the services EJBs are able to provide. To help streamline usage, EJB API groups were cre-
ated for EJB 3.2. EJB API groups are well-defined subsets of the capabilities of EJBs cre-
ated for specific purposes. The groups defined in the EJB 3.2 specification are these:
• EJB Lite
• Message-driven beans
• EJB 3.x Remote
• Persistent EJB timer services
• JAX-WS Web Service endpoints
• Embeddable EJB container (optional)
• EJB 2.x API
• Entity beans (optional)
• JAX-RPC Web Service endpoints (optional)
Except for the few groups that are optional, a full EJB container is required to implement
all of the groups. The most important of these is the EJB Lite group. The EJB Lite group
consists of the minimum number of EJB features that's still powerful enough to handle the
majority of business transactions and security needs. This makes an EJB Lite implementa-
tion ideal to embed into a Servlet container like Tomcat to give the container some Enter-
prise features, or you can embed it into your Android tablet application to handle its data
needs.
Now that we've looked at some of the new features and changes made to EJB 3.2, let's
see how EJB technology compares with other frameworks in the marketplace that are also
attempting to provide solutions for Enterprise Java software development.
