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II Write the WSDL (Web Service Definition Language)

Build a full web service with Axis

WSDL file structure

The Web Service Definition Language allow to define a whole web service :

• service : defines addresses where the SOAP services can be call.
• portType : groups messages for the specified operation. Each operation consists in one input message and one or more output messages.
• binding : defines how to invoke the service.
• message : defines a message. A message can be a request message or a response message.
• types : defines data types shared by both the service provider and the service requester.

A web service can be entirely specified by it's wsdl file.

Service definition

Our web service will be available at the http://localhost:8080/AxisTutorialServer/services/AxisTutorialSOAP URL. It's name is AxisTutorial

definition.wsdl

<wsdl:service name="AxisTutorial"> <wsdl:port binding="tns:AxisTutorialSOAP" name="AxisTutorialSOAP"> <soap:address location="http://localhost:8080/AxisTutorialServer/services/AxisTutorialSOAP"/> </wsdl:port> </wsdl:service>

Function and messages definition

The AxisTutorial contains the exposed functions signature. The GetById functions takes a GetByIdRequest input parameter and returns a GetByIdResponse output. The binding is used to define the transport of both the input and the output (SOAP literal in our example).

definition.wsdl

<wsdl:portType name="AxisTutorial"> <wsdl:operation name="GetById"> <wsdl:input message="tns:GetByIdRequest"/> <wsdl:output message="tns:GetByIdResponse"/> </wsdl:operation> </wsdl:portType> <wsdl:binding name="AxisTutorialSOAP" type="tns:AxisTutorial"> <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/> <wsdl:operation name="GetById"> <soap:operation soapAction="http://axis.tutorial/AxisTutorial/GetById"/> <wsdl:input> <soap:body use="literal"/> </wsdl:input> <wsdl:output> <soap:body use="literal"/> </wsdl:output> </wsdl:operation> </wsdl:binding>

Messages definition

Both request and response messages are defined as transporting one message part. Each part maps to a specific type.

definition.wsdl

<wsdl:message name="GetByIdRequest"> <wsdl:part element="tns:GetById" name="parameters"/> </wsdl:message> <wsdl:message name="GetByIdResponse"> <wsdl:part element="tns:GetByIdResponse" name="parameters"/> </wsdl:message>

Types definition

The two main types we are going to use are the GetById and the GetByIdResponse types. The first one is made of a single long attribute named in representing the id of the requested CD. The second one is made of one complex CD element named out and representing the requested CD. The complex CD type maps a CD in our catalog with it's id, name, artistName and publishDate parameters.

definition.wsdl

<wsdl:types> <xsd:schema targetNamespace="http://axis.tutorial/AxisTutorial/"> <xsd:element name="GetById"> <xsd:complexType> <xsd:sequence> <xsd:element name="in" type="xsd:long"/> </xsd:sequence> </xsd:complexType> </xsd:element> <xsd:element name="GetByIdResponse"> <xsd:complexType> <xsd:sequence> <xsd:element name="out" type="tns:CD"/> </xsd:sequence> </xsd:complexType> </xsd:element> <xsd:complexType name="CD"> <xsd:sequence> <xsd:element maxOccurs="1" minOccurs="1" name="id" nillable="false" type="xsd:long"/> <xsd:element maxOccurs="1" minOccurs="1" name="name" nillable="true" type="xsd:string"/> <xsd:element maxOccurs="1" minOccurs="1" name="artistName" nillable="true" type="xsd:string"/> <xsd:element maxOccurs="1" minOccurs="1" name="publishDate" nillable="true" type="xsd:date"/> </xsd:sequence> </xsd:complexType> </xsd:schema> </wsdl:types>

Simple types in a xsd schema such as string, date, long, ... could be length or value restricted. For example, we could write :

definition.wsdl

<xsd:complexType name="CD"> <xsd:sequence> <xsd:element maxOccurs="1" minOccurs="1" name="id" nillable="false" type="xsd:long"/> <xsd:element maxOccurs="1" minOccurs="1" name="name" nillable="true" type="tns:name"/> <xsd:element maxOccurs="1" minOccurs="1" name="artistName" nillable="true" type="tns:artistName"/> <xsd:element maxOccurs="1" minOccurs="1" name="publishDate" nillable="true" type="xsd:date"/> </xsd:sequence> </xsd:complexType> <simpleType name="name"> <restriction base="xsd:string"> <maxLength value="20"/> <pattern value="[-a-zA-Z ]+"/> </restriction> </simpleType> <simpleType name="artistName"> <restriction base="xsd:string"> <maxLength value="20"/> <pattern value="[-a-zA-Z ]+"/> </restriction> </simpleType>

We wont use this restrictions in our example.

Download the full wsdl file

Continue to part III : Service provider implementation (Top down Java Web Service)

For more information about the Web Service Definition Language check :

• WSDL 1.1 specifications
• WSDL 2.0 specifications
• WSDL tutorial (at www.W3schools.com)

Axis Web Service

• Web service specification
• Web service definition - WSDL
• Axis server implementation
• Axis client implementation
• Axis handler
• Axis TCP monitor
• Axis SOAP/XML incoming request validation

Frameworks :

• Axis web service
  Build a full web service with Axis
• Axis2 web service
  Build a full web service with Axis2

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