WSDL anatomy

WSDL files are written in XML. To learn more about XML, see Web services: Resources for learning.

A WSDL contains the following parts...

• Web service interface definition

  This is where the elements are contained, as well as the namespaces.

• Web service implementation

  This is where you find the definition of the service and ports.

A WSDL file describes a Web service with the following elements...

portType

The description of the operations and their associated messages. PortTypes define abstract operations

<portType name="EightBall">
    <operation name="getAnswer">
        <input message="ebs:IngetAnswerRequest"/>
        <output message="ebs:OutgetAnswerResponse"/>
    </operation>
</portType>

message

The description of parameters (input and output) and return values

<message name="IngetAnswerRequest">
    <part name="meth1_inType" type="ebs:questionType"/>
</message>
<message name="OutgetAnswerResponse">
    <part name="meth1_outType" type="ebs:answerType"/>
</message>
        

types

The schema for describing XML complex types used in the messages

<types>
    <xsd:schema targetNamespace="...">
        <xsd:complexType name="questionType">
            <xsd:element name="question" type="string"/>
        </xsd:complexType>
        <xsd:complexType name="answerType">
        ...
</types>

binding

Bindings describe the protocol used to access a service, as well as the data formats for the messages defined by a particular portType

<binding name="EightBallBinding" type="ebs:EightBall">
    <soap:binding style="rpc" transport="schemas.xmlsoap.org/soap/http">
    <operation name="ebs:getAnswer">
    <soap:operation soapAction="urn:EightBall"/>
        <input>
            <soap:body namespace="urn:EightBall" ... />
        ...

The remaining parts, services and ports, indicate where you can find the WSDL.

Service

Ports

<service name="EightBall">
    <port binding="ebs:EightBallBinding" name="EightBallPort">
        <soap:address location="localhost:8080/axis/EightBall"/>
    </port>
</service>