WSDL and UDDI

WSDL (Web Services Description Language) is an XML-based language for describing Web services and how to access them. It specifies the location of the service and the operations (or methods) the service exposes.

The main structure of a WSDL document looks like this:

<definitions>
  <types>   
     definition of the data types used by the web service...
  </types>  
  <message> 
     definition of the messages used by the web service...
  </message>
  <portType>
     definition of the operations performed by the web service...
  </portType>
  <binding> 
     definition of the communication protocols used by the web service...
  </binding>
</definitions>

WSDL Ports
The <portType> element is the most important WSDL element.
It describes a web service, the operations that can be performed, and the messages that are involved. It can be compared to a function library (or a module, or a class) in a traditional programming language. Each <operation> inside <portType> can be compared to a function in a traditional programming language.

<portType name="glossaryTerms">
   <operation name="setTerm">
      <input name="newTerm" message="newTermValues"/>
   </operation>
   <operation name="...">
      ...
   </operation>
</portType >

WSDL Messages
The <message> element defines the data elements of an operation.
Each message can consist of one or more parts. The parts can be compared to the parameters of a function call in a traditional programming language.

<message name="getTermRequest">
   <part name="term" type="xs:string"/>
</message>
<message name="getTermResponse">
   <part name="value" type="xs:string"/>
</message>
<portType name="glossaryTerms">
  <operation name="getTerm">
      <input message="getTermRequest"/>
      <output message="getTermResponse"/>
  </operation>
</portType>

WSDL Types
The <types> element defines the data type that are used by the web service.

WSDL Bindings
The <binding> element defines the message format and protocol details for each port.

What is UDDI

Universal Description, Discovery and Integration (UDDI) is a platform-independent framework for describing services, discovering businesses, and integrating business services by using the Internet.

• UDDI is a directory for storing information about web services
• UDDI is a directory of web service interfaces described by WSDL
• UDDI communicates via SOAP