Java Reference
In-Depth Information
In general, this specification does not initiate any new major feature. It continues the
work started by the last version, making optional the implementation of certain fea-
tures that became obsolete and adds slight modification to others.
Pruning some features
After the pruning process introduced by Java EE 6 from the perspective of removing
obsolete features, support for some features has been made optional in Java EE 7
platform, and their description was moved to another document called
EJB 3.2 Op-
tional Features for Evaluation
. The features involved in this movement are:
• EJB 2.1 and earlier Entity Bean Component Contract for Container-Managed
Persistence
• EJB 2.1 andearlier Entity Bean Component Contract for Bean-Managed Per-
sistence
• Client View of EJB 2.1 and earlier Entity Bean
• EJB QL: Query Language for Container-Managed Persistence Query Meth-
ods
• JAX-RPC-based Web Service Endpoints
• JAX-RPC Web Service Client View
The latest improvements in EJB 3.2
For those who have had to use EJB 3.0 and EJB 3.1, you will notice that EJB 3.2 has
brought, in fact, only minor changes to the specification. However, some improve-
ments cannot be overlooked since they improve the testability of applications, simpli-
fy the development of session beans or Message-Driven Beans, and improve control
over the management of the transaction and passivation of stateful beans.
Session bean enhancement
A session bean is a type of EJB that allows us to implement business logic access-
ible to local, remote, or Web Service Client View. There are three types of session
beans:
stateless
for processing without states,
stateful
for processes that require
thepreservationofstatesbetweendifferentcallsofmethods,and
singleton
forshar-
ing a single instance of an object between different clients.
