EAServer

PowerBuilder and EAServer are
fully integrated. A PowerBuilder application can act as a client
to any EAServer component. In
addition, EAServer can contain
PowerBuilder custom class user (nonvisual) objects that execute
as middle-tier components.

EAServer hosts the PowerBuilder
virtual machine natively. This means that EAServer can
communicate directly with PowerBuilder nonvisual user objects, and
vice versa. EAServer components
developed in PowerBuilder can take full advantage of the ease of
use and flexibility of PowerScript and the richness of PowerBuilder’s
system objects.

Components developed in PowerBuilder can exploit features
such as transactions, interoperability, and instance pooling. As
shown in Figure 22-1, any
type of client can access any type of component running in EAServer, regardless of the language
used to develop the component.

Figure 22-1: Clients and components in EAServer

For more information, see Chapter 23, “Building an EAServer Component” and Chapter 24, “Building an EAServer Client .”

J2EE servers

J2EE, the Java 2 Platform, Enterprise Edition, is the official
Java framework for enterprise application development. A J2EE application
is composed of separate components that are installed on different
computers in a multitiered system. Figure 22-2 shows three tiers in this system:
the client tier, middle tier, and Enterprise Information Systems
(EIS) tier. The middle tier is sometimes considered to be made up
of two separate tiers: the Web tier and the business tier.

Figure 22-2: J2EE client, middle, and
EIS tiers

Client components, such as application clients and applets,
run on computers in the client tier. Web components, such as Java
servlets and JavaServer Pages (JSP) components, run on J2EE servers
in the Web tier. Enterprise JavaBeans (EJB) components are business
components and run on J2EE servers in the business tier. The EIS
tier is made up of servers running relational database management
systems, enterprise resource planning applications, mainframe transaction
processing, and other legacy information systems.

In PowerBuilder, you can build client applications that use
the services of EJB components running on any J2EE-compliant server.
For more information, see Chapter 27, “Building an EJB client .”

Plug-in for J2EE servers

You can also deploy custom class user objects to third-party
application servers on which the PowerBuilder Application Server
Plug-in is installed. The plug–in is a Sybase product that
supports several application servers. Wizards that help you generate
application server components that you can deploy to these servers
and proxies that you can use to build client applications are built
into PowerBuilder, but you must install the plug-in product separately.
The wizards and techniques are very similar to those used for building EAServer components and clients.
For more information, see the documentation for the PowerBuilder
Application Server Plug–in on the Product Manuals Web site
.

COM+

A PowerBuilder application can act as a client to a COM server.
The server can be built using any COM-compliant application development
tool and it can run locally, on a remote computer as an in-process
server, or in COM+.

For more information, see Chapter 26, “Building a COM or COM+ Client.”