Web Services

Q1. what is Protocols that helps Web Services ?
Answer: Web Services used three protocols for interacting with the clients.Http-Post,Http-Get,SOAP.

Q2. what is functioning of Web Services Protocols ?
Answer: Http-Get:- This is standard protocol that helps client to communicate with server with HTTP.When client send a request to server via HTTP request and reuired parameter are attached with the querystring.

Http-Post:-This is same as Http-Get but the diffrence is that in place of sending parameters onto the URL information is send with HTTP request message with some extra information which contains Parameters and their values.This Protocols is limited to sending name/value pairs.

SOAP:-The only diffrence that its relies on XML as compares to Http-Get,Http-Post.SOAP can send not only name/value pairs but also some complex object also as for example datatypes,class,objects.SOAP can also uses request/reponse model as Http-Get,Http-post but it is not limited to Request/Response it can also send types of message.Because its uses XML that is pure text so firewalls not created so much problem because its easily converted in to HTML. .

Q3. Why do some web service classes derive from System.Web.WebServices while others do not ?
Answer: Those Web Service classes which employ objects like Application, Session, Context, Server, and User have to derive from System.Web.WebServices. If it does not use these objects, it is not necessary to be derived from it.

Q. What do you mean is WSDL ?
Answer: WSDL is an XML format for describing network services as set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). (Source: www.w3.org).

Q5. What is the standard you use to wrap up a call to a Web service ?
Answer: HTTP with SOAP.

Q6. Explain Web Services ?
Answer: Web services are programmable business logic components that provide access to functionality through the Internet. Standard protocols like HTTP can be used to access them. Web services are based on the Simple Object Access Protocol (SOAP), which is an application of XML. Web services are given the .asmx extension..

Q7. What are VSDISCO files ?
Answer: VSDISCO files are DISCO files that enable dynamic discovery of Web Services. ASP.NET links the VSDISCO to a HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document.

Q8. What is UDDI ?
Answer: UDDI stands for Universal Description, Discovery, and Integration. It is like an "Yellow Pages" for Web Services. It is maintained by Microsoft, IBM, and Ariba, and is designed to provide detailed information regarding registered Web Services for all vendors. The UDDI can be queried for specific Web Services.

Q9. Is it possible to generate the source code for an ASP.NET Web service from a WSDL ?
Answer: The Wsdl.exe tool (.NET Framework SDK) can be used to generate source code for an ASP.NET web service with its WSDL link.
Example: wsdl /server http://api.google.com/GoogleSearch.wsdl.