WebSphere Adapters implement the Java 2 Enterprise Edition (J2EE) Connector
Architecture (JCA) version 1.5. They are referred to as WebSphere Adapters
or Resource Adapters. They manage bidirectional connectivity between enterprise
information systems (EISs) and J2EE components supported by WebSphere Process Server.
JCA is designed to facilitate data sharing and to integrate new J2EE applications
with legacy and other EISs. JCA stipulates how to develop a WebSphere Adapter
that can:
- Plug into any J2EE-compliant application server.
- Connect an application running on that server with an EIS.
- Enable data exchange between the J2EE application and the EIS.
The JCA standard accomplishes this by defining a series of contracts that
govern interactions between an EIS and J2EE components within an application
server. Fully compliant with the JCA standard, WebSphere Adapters have been
developed to run on
WebSphere Process Server.
Compliance with JCA has several advantages:
- JCA is an open standard,
- JCA is the J2EE standard for EIS connectivity,
- JCA provides a managed framework.
Each WebSphere Adapter is made up of the following:
- Foundation classes These implement a generic set of contracts that WebSphere Process Server uses
to manage interactions between J2EE applications and all WebSphere Adapters.
These quality of service and life cycle management contracts, also known as
system contracts, define the service provider interface (SPI). For example,
system contracts specify security credential management, connection pooling
and transaction management parameters.
- EIS subclasses These generic and EIS-specific subclasses define
the Common Client Interface (CCI) and EIS API contracts. For example, Activation
and Connection Specs allow WebSphere Process Server to
manage incoming and outgoing events for the WebSphere Adapter.
- Enterprise Metadata Discovery This utility introspects the EIS
to generate service data objects (SDOs) and other artifacts that are compiled
in a standard Enterprise Application Archive (EAR) file.
A simplified version of the operation of a WebSphere Adapter is shown
schematically in figure 1:
Figure 1. Simplified schematic of a WebSphere
Adapter.