WSIF and WSDL
WSDL is the acronym for Web
Services Description Language.
In WSDL a service is defined in three distinct sections:
- The portType. This section defines the abstract interface offered
by the service. A portType defines a set of operations. Each operation
can be In-Out (request-response), In-Only, Out-Only and Out-In (Solicit-Response).
Each operation defines the input and/or output messages. A message
is defined as a set of parts, and each part has a schema-defined type.
- The binding. This section defines how to map between the abstract
portType and a real service format and protocol. For example the SOAP binding
defines the encoding style, the SOAPAction header, the namespace of the body
(the targetURI), and so on.
- The port. This section defines the actual location (endpoint) of the available
service. For example, the HTTP Web address at which a SOAP service is available.
Currently in WSDL, each port has one and only one binding, and each binding
has a single portType. But (more importantly) each service (portType) can
have multiple ports, each of which represents an alternative location and
binding for accessing that service.
The Web Services Invocation Framework (WSIF) follows the semantics of WSDL as much as possible:
- The WSIF dynamic invocation API
directly exposes run-time equivalents of the model from WSDL. For example,
invocation of an operation involves executing an operation with an
input message.
- WSDL has extension points that support the addition of new ports and bindings. This enables WSDL to describe new systems.
The equivalent concept in WSIF is a provider, that enables WSIF to understand
a class of extensions and thereby to support a new service implementation type.
As a metadata-based invocation framework, WSIF follows the design of the
metadata. As WSDL is extended, WSIF is updated to follow.
The implicit and primary type system of WSIF is XML schema. WSIF supports invocation using dynamic proxies,
which in turn support Java type systems, but when you use the
WSIFMessage interface it is your responsibility to populate WSIFMessage objects with data based on
the XML schema types as defined in the WSDL document. You should define your object types by a canonical and fixed
mapping from schema types into the run-time.
For more information on WSDL, see Web services: Resources for learning.

An overview of WSIF
WSIF architecture
Using WSIF with Web services that offer multiple bindings
WSIF usage scenarios
Dynamic invocation
Searchable topic ID:
cwsf_wsdl
Last updated: Jun 21, 2007 8:07:48 PM CDT
WebSphere Business Integration Server Foundation, Version 5.0.2
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