WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

Another good source of information is IBM Redbooks publication Building
Dynamic Ajax Applications Using WebSphere Feature Pack for Web 2.0,
SG24-7635. This book contains an in-depth description of this feature pack and it
is an essential reference for those planning to use it.
13.3 WebSphere Application Server Feature Pack for
Service Component Architecture
This section describes the new IBM WebSphere Application Server V7.0 Feature
Pack for Service Component Architecture (SCA). It introduces SCA and explains
what is in the feature pack.
13.3.1 Introduction to SCA
SCA is a set of specifications that constitute a programming model for building
applications using a service-oriented architecture (SOA). SCA extends other
SOA technologies, like Web services, while providing a platform and
language-neutral component model based on open standards specified by the
Open SOA Collaboration (OSOA).
The main objective of SCA is allowing the creation of complex composite
applications based on previously existing service components.
Key principles
SCA is based on three key principles:
► Service composition
SCA offers a composition model that allows you to build new services from
existing software components. SCA provides the metadata for describing
these components and the connections between them while hiding their inner
workings.
► Service development
SCA has a language-neutral programming model. There are
language-specific models for Java, Spring, C++, and other languages.
Because SCA defines a common assembly mechanism, the language used
for implementing a service does not need to be known by the service
consumer.
► Service agility and flexibility
The component model provided by SCA makes the composition and
assembly of business logic simple and allows a flexible reusability of
components. A component can be easily replaced by another component
providing the same service.
412 WebSphere Application Server V7.0: Concepts, Planning, and Design