At a high level, a WSDL document is a contract between a
service and its consumers. The contract provides such critical
information as the service endpoint, the service operations, and the
data types required for these operations. The service contract also
indicates, in describing the messages exchanged in the service, the
underlying service pattern, for instance, request/response or
solicit/response. The outermost element (called the
document or root element) in a
WSDL is named
definitions because the
WSDL provides definitions grouped into the following sections:
which is optional, provides data type definitions under
some data type system such as XML Schema. A particular document that
defines data types is an XSD (XML Schema
holds, points to, or imports an XSD. If the
types section is empty, as in the case of
TimeServer service, then the
service uses only simple data types such as
Although the WSDL 2.0 specification allows for alternatives to XML Schema (see http://www.w3.org/TR/wsdl20-altschemalangs), XML Schema is the default and the dominant type system used in WSDLs. Accordingly, the following examples assume XML Schema unless otherwise noted.
section defines the messages that implement the service.
Messages are constructed from data types either defined in the
immediately preceding section or, if the
types section is empty, available as defaults. Further, the order of the ...