Structure of a WSDL Document

Web Services Description Language (WSDL) is an XML grammar for describing network services as collections of communication endpoints capable of exchanging messages. The diagram below illustrates the elements that are present in a WSDL document, and indicates their relationships. To see an example of how this is implemented in a WSDL document, refer to the Example of a WSDL Document.

WSDL Document Elements

A WSDL document has a definitions element that contains the other five elements, types, message, portType, binding and service. The following sections describe the features of the generated client code.

WSDL supports the XML Schemas specification (XSD) as its type system.

definitions

Contains the definition of one or more services. JDeveloper generates the following attribute declarations for this section:

• name is optional.
• targetNamespace is the logical namespace for information about this service. WSDL documents can import other WSDL documents, and setting targetNamespace to a unique value ensures that the namespaces do not clash.
• xmlns is the default namespace of the WSDL document, and it is set to http://schemas.xmlsoap.org/wsdl/.
• All the WSDL elements, such as <definitions>, <types> and <message> reside in this namespace.
• xmlns:xsd and xmlns:soap are standard namespace definitions that are used for specifying SOAP-specific information as well as data types.
• xmlns:tns stands for this namespace.
• xmlns:ns1 is set to the value of the schema targetNamespace, in the <types> section.

Notice that the default of http://tempuri.org in namespaces to ensure that the namespaces are unique.

types

Provides information about any complex data types used in the WSDL document. When simple types are used the document does not need to have a types section.

message

An abstract definition of the data being communicated. In the example, the message contains just one part, response, which is of type string, where string is defined by the XML Schema.

operation

An abstract description of the action supported by the service.

portType

An abstract set of operations supported by one or more endpoints.

binding

Describes how the operation is invoked by specifying concrete protocol and data format specifications for the operations and messages.

port

Specifies a single endpoint as an address for the binding, thus defining a single communication endpoint.

service

Specifies the port address(es) of the binding. The service is a collection of network endpoints or ports.