This section shows you the “big picture”—what CICS® support for
Enterprise JavaBeans means in general terms. The sections that
follow fill in the details.
Sun Microsystem's Enterprise JavaBeans Specification,
Version 1.1, defines a model for the development of reusable Java™ server components (known as enterprise beans) that can be used in any application server that
provides the services and interfaces defined by the specification.
You can configure CICS as an EJB server. CICS
provides a run-time environment where requests for EJB services are mapped
to existing or enhanced CICS services.
You can write enterprise beans that give Java clients access to your past
investment in CICS applications and data. For example, you can write enterprise
beans that:
- Use the JCICS classes1 to access CICS resources.
- Use JCICS or the CCI Connector for CICS TS to link to existing CICS programs written in
procedural languages such as COBOL. (For information about the CCI Connector for CICS TS,
see topic The CCI Connector for CICS TS.)
Figure 1 shows, in simplified form, a CICS EJB application
server interacting with its environment. It shows enterprise beans that have
been developed on a workstation being installed into the EJB server by a process
known as
deployment. Once installed in the server, the
enterprise beans are executed in a Java Virtual Machine (JVM) at the request
of a client program.
Note: The details of
Figure 1 are
explained in the sections that follow.
Figure 1. A
CICS EJB application server.
Enterprise beans developed on a workstation
are installed into the EJB server by a process known as deployment. They are
executed in a JVM at the request of a client program. The details of this
picture are explained in the sections that follow.