WSDL study

http://www.w3schools.com/wsdl/default.asp

 

 

WSDL Tutorial

WSDL (Web Services Description Language) is an XML-based language for describing Web services and how to access them.

 

 

Table of Contents

Introduction to WSDL
This introduction to WSDL explains what WSDL is.

WSDL Documents
This chapter explains the main parts of an WSDL document.

WSDL Ports
This chapter explains the WSDL port interface.

WSDL Binding
This chapter explains the WSDL binding interface.

WSDL and UDDI
This chapter explains how UDDI (Universal Description Discovery and Integration) is integrated with WSDL.

WSDL Syntax
The full WSDL syntax as listed in the W3C note.

 

 

 

 

WSDL is used to describe Web services

WSDL is also used to locate Web services

 

 

 

A WSDL document describes a web service using these major elements:

ElementDefines

<portType>	The operations performed by the web service
<message>	The messages used by the web service
<types>	The data types used by the web service
<binding>	The communication protocols used by the web service

 

The <portType>  can be compared to a function library (or a module, or a class) in a traditional programming language.

<message> can be compared to the parameters of a function call in a traditional programming language.

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

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

 

 

WSDL Ports

The <portType> element is the most important WSDL element.

It defines a web service, the operations that can be performed, and the messages that are involved.

<portType name="glossaryTerms"> 
  <operation name="getTerm">     
    <input message="getTermRequest"/>      
    <output message="getTermResponse"/>  
  </operation>
</portType>

 

 

 

 

 

<binding type="glossaryTerms" name="b1">
<soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http" />
  <operation>
    <soap:operation soapAction="http://example.com/getTerm"/>
    <input>
      <soap:body use="literal"/>
    </input>
    <output>
      <soap:body use="literal"/>
    </output>
  </operation>
</binding>

 

 

The binding element has two attributes - the name attribute and the type attribute.

The name attribute (you can use any name you want) defines the name of the binding, and the type attribute points to the port for the binding, in this case the "glossaryTerms" port.

 

The soap:binding element has two attributes - the style attribute and the transport attribute.

The style attribute can be "rpc" or "document". In this case we use document. The transport attribute defines the SOAP protocol to use. In this case we use HTTP.

 

 

The operation element defines each operation that the port exposes.

For each operation the corresponding SOAP action has to be defined. You must also specify how the input and output are encoded. In this case we use "literal".

 

 

UDDI uses WSDL to describe interfaces to web services