Web services
Web services are self-contained, modular applications that can be described, published, located, and invoked over a network.
WAS supports Web services that are developed and implemented based on the Web Services for J2EE specification.
A typical Web services scenario is a business application requesting a service from another existing application. The request is processed through a given Web address using SOAP messages over a HTTP, JMS transport or invoked directly as EJB.
The service receives the request, processes it, and returns a response. Examples of a simple Web service include weather reports or getting stock quotes. The method call is synchronous, that is, it waits until the result is available.
Transaction Web services, supporting quotes, business-to-business (B2B) or business-to-client (B2C) operations include airline reservations and purchase orders.
Web services can include the actual service or the client that accesses the service.
Web services reflect the service-oriented architecture (SOA) approach to programming, which is based on the idea of building applications by discovering and implementing network-available services, or by invoking the available applications to accomplish a task.
Web services deliver interoperability allowing components created in different programming languages to work together. Web services rely on existing transport technologies, such as HTTP, and standard data encoding techniques, such as XML, for invoking the implementation.
The key components of Web services include:
- Web Services Description Language (WSDL)
WSDL is the XML-based file that describes the Web service. The Web service request uses this file to bind to the service.
- SOAP
SOAP is the XML-based protocol that the Web service request uses to invoke the service.
- Universal Description, Discovery and Integration Protocol (UDDI)
UDDI is the registry that hosts the service broker. UDDI is similar to the Yellow Pages in a phone book.
For a more detailed scenario, see Web services scenario: Overview, which tells the story of a fictional online garden supply retailer named Plants by WebSphere, and how this retailer incorporated the Web services concept.
Sub-topics
Web Services for J2EE specification
Artifacts used to develop Web services
WSDL
SOAP
JAX-RPC
Web Services-Interoperability Basic Profile
WS-I Attachments Profile
Related concepts
Web Services for J2EE specification
Related tasks
Use the UDDI registry
Enabling Web services through service integration technologies
WS-Notification - publish and subscribe messaging for Web services
Related Reference
Web services: Resources for learning