As one of the cornerstones of Web services technology which is commonly used to implement SAP's Enterprise SOA, WSDL is essentially an XML format for describing Web services interfaces. Using WSDL, a service provider can describe the functionality, quality of service requirements, and other features of a Web service, so that a potential requestor can understand how to correctly interact with the service. SAP NetWeaver not only provides tools for generating and consuming WSDL definitions, but also provides an Enterprise Services Repository (ESR) for defining and managing enterprise service interfaces using WSDL.
WSDL1.1 is a W3C member submission co-submitted by SAP and its technology partners, including Microsoft and IBM. Combined with the guidance of WS-I Basic Profiles, WSDL 1.1 is widely supported in all Web services platforms including SAP NetWeaver.
W3C has created a working group under its Web Services Activity to standardize the language for Web services description. Taking WSDL1.1 as the initial input, the W3C working group is working on WSDL2.0.
Getting Started
An Overview of Web Service Interoperability
The goal of integrating independent IT systems with Web services was almost cut short by a lack of interoperable implementations, even though they were based on the same specifications. This paper outlines how this situation arose, what has been done to date, and continuing efforts.
Web Services Description Language (WSDL) is an XML format for describing web services, and plays a central role for interoperability among services implemented in different platforms. This article provides an update on the status of WDSL 2.0 and describes how it differs from WDSL 1.1.
Specifications and Whitepapers
The W3C member submission version of WSDL specification.
WSDL 1.1 Binding Extension for SOAP 1.2
This specification defines WSDL 1.1 binding extensions to indicate that Web service messages are bound to the SOAP 1.2 protocol.
This document provides an introduction to WSDL 2.0.
This W3C specification describes the how to use WSDL 2.0 with the SOAP 1.1 protocol.
This W3C specification describes the Web Services Description Language Version 2.0 (WSDL 2.0), an XML language for describing Web services. This specification defines the core language which can be used to describe Web services based on an abstract model of what the service offers. It also defines the conformance criteria for documents in this language.
This document defines predefined extensions for use in WSDL 2.0:- Message exchange patterns- Operation styles- Binding Extensions
Related Activities
W3C WSDL (Web Services Description) Working Group
SAP is a participant in this working group and co-submitter. The W3C Working Group that is developing the WSDL specification.
More on Web Services Description Language (WSDL)
Describing Web Service Semantics with WSDL
IBM and University of Georgia have recently submitted a notes to W3C for the description of the semantics of a Web service. The title of the note, Web Service Semantics - WSDL-S , is somewhat misleading, but the idea proposed really worth's some attention.
Light At the End of the Tunnel?
WSDL 2.0 will soon be moving to Candidate Recommendation phase in W3C.
A note on wsdl and xsd imports - part II
It has been a while since I first wrote about WSDL and schema imports based on WS-I BP recommendations. In the last year, W3C has done a lot of work to resolve the problem in WSDL2.0. Here is an update about the WSDL 2.0 solution.
The myth of placement of WSDL elements and extensions
A note on placement of wsdl elements and extensions - where they can go in a WSDL1.1 description, what WS-I has to say.
A note on wsdl and xsd imports
If you implement a web service tool, especially a wsdl processor, you may have already been deeply confused about how import works in WSDL. If you are a web service developer, you may have been puzzled by the WSDLs generated by your selected tool since . . .
Related Areas on SDN
An Overview of Web Service Interoperability
The goal of integrating independent IT systems with Web services was almost cut short by a lack of interoperable implementations, even though they were based on the same specifications. This paper outlines how this situation arose, what has been done to date, and continuing efforts.
Associated Standards/Organizations
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