Java Reference
In-Depth Information
There are more deployment options for Java Card applets, such as Rom applets. We have cov-
ered here a simple, though complete, deployment scenario.
And now, from one end to the other of the Java computational range: the Java 2 Enterprise
Edition platform.
J2EE Deployment
Despite the J2EE widespread presence on the server, we will introduce it briefly here, to dis-
cuss the deployment scenario for this platform. The interested reader can see
Building Java
Enterprise Systems With J2EE
, by Paul Perrone (published by SAMS), which is one of the
many topics on this subject. Given the abundance of publications on this topic, we will only
cover it briefly. J2EE applications are aimed at server-based, rich computational environments,
in contrast with the platforms covered earlier in this chapter. Here, hardware constraints and
low-level issues are not a problem.
A Brief Introduction
First of all, here is a little overview of the involved roles. The EJB specification partitions the
responsibility of development and deployment to up to six well-known roles. These can be
individuals, teams, or separated firms, as follows:
•
The bean provider
provides reusable business components adhering to the EJB specifi-
cation.
•
The container provider
offers the software container needed to run EJB components.
•
The server provider
supplies the application server software.
•
The application assembler
is responsible for the overall application architecture, inte-
grating together existing components or writing them from scratch as needed to produce
the final application. The assembler must understand (along with the application work-
flow) all the settings needed to be specified to successfully customize and deploy the
final application.
•
The deployer
is responsible for installing the application components (that is, the output
of the application assembler) in the target application servers. The deployer needs to be
aware of the differences between the various servers, containers, and beans involved in
the deployment. Another important issue is the adaptation of the deployed application to
the current security settings and other customer-sensitive data.
•
The system administrator
takes care of the deployed application during its running in
an operational environment.
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