Java Reference
In-Depth Information
WS-Reliability, Security Assertion Markup Language (SAML), and
other XML-based e-commerce standards such as ebXML are
developed by the OASIS standards group; for more details on these
standards refer to [OASIS 2006]. The WS-I, a Web services interoper-
ability organization, defines Web services usage recommendations
based on real-world issues to promote interoperability between var-
ious software platforms; for more details refer to [WSI 2006].
JDMWS is compliant with WS-I Basic Profile 1.0.
Service-Oriented Architecture
With the advent of Web services and other XML standards, Service-
Oriented Architecture (SOA) is gaining acceptance as an application
architecture. SOA provides needed flexibility for ever-changing busi-
ness requirements. SOA typically uses Web services as the base tech-
nology that enables legacy application functionality as services that
can be orchestrated using standards such as the Business Process
Execution Language (BPEL, often pronounced “bee-pel”) to define
business processes. BPEL is an XML-based business process design
and execution standard language that is receiving wide adoption by
applications to define and manage business processes. There are
many commercial BPEL engines [BPEL-ENGINES 2006], which typi-
cally are used to design business processes using a graphical tool and
deploy these processes to a BPEL engine. The BPEL engine executes
the BPEL processes and provides graphical user interfaces for man-
aging these deployed processes. For more details refer to [BPEL
Figure 11-3 illustrates the typical SOA layers. The bottom layer,
Layer 1, represents the legacy systems and applications that evolved
in an enterprise over time; these can come from a variety of sources
including mainframe systems, open systems, prepackaged software
like ERP, CRM applications, or homegrown applications. Layer 2
represents the components layer that uses container-based technolo-
gies such as Enterprise Java Beans (EJB) in J2EE. Typically this layer
is built using components-based design patterns to define reusable
components at a higher-level of abstraction than the detailed object
level functionality. Layer 3 represents the services layer. A service can
be a composite service that uses the functionality of multiple compo-
nents. Layer 4 defines the business process flows using orchestration
services such as BPEL. Layer 5 represents the presentation layers,
such as portals, and dashboards. Layer 6 enables integration
of services popularly known as the Enterprise Service Bus (ESB).
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