WSDL (Web Services Description Language) Interview Questions And Answers

WSDL is stands for Web Services Description Language. Basically WSDL is fully based on XML.Main use of WSDL to describe the web services and also told how to use this web services.It is written on XML. Also WSDL has W3C Recommendation

WSDL given us many element to describe its document. I have only given you four elements which are main elements to describing WSDL document.
These are:
1. <portType> is an important element to describe WSDL document.Using this element we can perform a task to compare a function library(like: class) in traditional programming language.
2. each <message> element has more than one parts.we can compare that parts.
3. using <types> we can define datatypes that are used in web services.
4.using <binding> for each port we can define the format of messages and details of protocol.
syntax:
<definitions>
<types>
To define type here
</types>
<message>
To define message here
</message>
<portType>
To define portType here
</portType>
<binding>
To define binding here
</binding>
</definitions>

SOAP (Simple Object Access Protocol) is a simple protocol
for exchange of information. It is based on XML and
consists of three parts: a SOAP envelope (describing what's
in the message and how to process it); a set of encoding
rules, and a convention for representing RPCs (Remote
Procedure Calls) and responses.
UDDI (Universal Description, Discovery, and Integration) is
a specification designed to allow businesses of all sizes
to benefit in the new digital economy. There is a UDDI
registry, which is open to everybody. Membership is free
and members can enter details about themselves and the
services they provide. Searches can be performed by company
name, specific service, or types of service. This allows
companies providing or needing web services to discover
each other, define how they interact over the Internet and
share such information in a truly global and standardized
fashion.
WSDL (Web Services Description Language) defines the XML
grammar for describing services as collections of
communication endpoints capable of exchanging messages.
Companies can publish WSDLs for services they provide and
others can access those services using the information in
the WSDL. Links to WSDLs are usually offered in a company?s
profile in the UDDI registry.

These are as follows SOAP, WSDL and UDDI. And I am explaining about the SOAP(Simple Object Access Protocol) it is a communication protocol it is for communication between application it is platform and language independent.It is based on XML and also help to get from Firwall.

The Wsdl.exe tool (.NET Framework SDK) can be used to generate source code for an ASP.NET web service with its WSDL link.

We can assume a web service as a method over the web, It actually takes the parameter and give the result in the XML format for independablity.furthermore, It use SOAP formatted XML enavlops and use WSDL for interfacing.

WSDL stands for Web Services Description Language. It is an XML representation of the web service interface.

There are two types of the operations specified in the WSDL file as represented by the <soap:binding> attribute of the file.

1. Document oriented operations -- are the ones which contain XML documents as input and output
2. Result oriented operations -- are the ones which contain input parameters as the input message and result as the output message

Basically we use binding in WSDL to define format of messages and detailed information about protocol of web services.
I have given you binding consist of two attributes.
these are name attribute and type attribute(name is used to define binding name where as type is used to define binding port.
I case of SOAP binding it has two attribute. These are style and transport attribute.
Example:
<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>
<binding type="glossaryTerms" name="b1">
<soap:binding style="document"
transport="http://xyzsoap.org/soap/http" />
<operation>
<soap:operation
soapAction="http://soapexample.com/getTerm"/>
<input>
<soap:body use="literal"/>
</input>
<output>
<soap:body use="literal"/>
</output>
</operation>
</binding>

At the command prompt:

WSDL http://ip address ofthe site/WebService/MathService.asmx /n:NameSp /out:FileName.cs]
-This will create a file called FileNmame.cs .

WSDL -> WebServices Description Language (This is an application available at C:Program

FilesMicrosoft.NETFrameworkSDKBin)

NameSp -> Name of the NameSpace which will be used in client code for deploying the

webservice.

2.Compilation

CSC /t:library /r:system.web.dll /r:system.xml.dll CreatedFile.cs

This will create a dll with the name of the public class of the asmx file.( In our case, it

is AddNumbers.dll )

CSC is an application available at C:WINNTMicrosoft.NETFrameworkv1.0.2914

3.Put the dll file inside WWWRooTBIN [Create a BIN Folder in WWWRoot]

A semantic annotation is additional information in a document that defines the semantics of a part of that document. In this technical note, the semantic annotations are additional information elements in a WSDL document. They define semantics by referring to a part of a semantic model that describes the semantics of the part of the document being annotated.

The WSDL document forms the anchor point for Web services description. Building on the descriptive capability of WSDL, a mechanism is provided to annotate the capabilities and requirements of Web services with semantic concepts referenced from a semantic model. To do this, mechanisms are provided annotate the service and its inputs, outputs and operations. Additionally, we provide mechanisms to specify and annotate preconditions and effects of Web Services.These preconditions and effects together with the semantic annotations of inputs and outputs can enable automation of the process of service discovery.

The easiest way to get started with Web services is to learn XML-RPC. Check out the XML-RPC specification or read my book, Web Services Essentials. O'Reilly has also recently released a book on Programming Web Services with XML-RPC by Simon St.Laurent, Joe Johnston, and Edd Dumbill.

Once you have learned the basics of XML-RPC, move onto SOAP, WSDL, and UDDI. These topics are also covered in Web Services Essentials. For a comprehensive treatment of SOAP, check out O'Reilly's Programming Web Services with SOAP, by Doug Tidwell, James Snell, and Pavel Kulchenko.