Apple WebObjects 5 - Manual (Page 87)

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Apple Computer, Inc. January 2002
C H A P T E R 7
7 J2EE Integration
Sun’s J2EE (Java 2, Enterprise Edition) platform aims at laying out an infrastructure
on which solutions (components or applications) from different vendors can work
together and share resources. In addition, it provides a framework on with n-tier
applications can be seamlessly deployed.
Enterprise JavaBeans (EJB) is an important part of J2EE. It provides an environment
in which components from several manufacturers can be assembled into a working
application. The application assembler, with deep knowledge of the requirements
of the business, can choose the component that best matches the task at hand. For
instance, she could use transaction-processing beans from one company; customer,
order, and product beans from another vendor; and shipping beans from a third
provider. She would then end up with an application capable of accepting orders,
charging the customer, and process shipments without having to write code.
JavaServer Pages (JSP) and servlets are also part of the J2EE architecture. JSP is a
specification that defines interfaces that vendors can implement to provide
developers the ability to create dynamic Web pages, which are files with the
extension
.jsp . HTTP servers that support JSP, interpret these files and create
servlets to process HTTP requests and produce responses. Servlets are server
plugins (specialized applications) that extend the capabilities of your HTTP server.
They provide a straightforward deployment mechanism for your applications.
Java Naming and Directory Service (JNDI) provides a mechanism through wich
components and applications can locate shared resources. For example, it allows
you to place a server-side resource anywhere in your system, while the application
that uses the resource only needs to know its name, not the name or IP address of
the host in which it resides.
The following sections give a more detailed explanation of each of these
technologies.