Web Service - FAQ

WEB SERVICE - Frequently Asked Question

1. What is SOAP?

Simple Object Access Protocol (SOAP) is a lightweight protocol for exchange of information in a decentralized, distributed environment. It's an industry-standard message format that enables message-based communications for Web services.

2. What is UDDI?

Universal Discovery Description and Integration is like the "Yellow Pages" of Web services. A UDDI directory entry is an XML file that describes a business and the services it offers. There are three parts to an entry in the UDDI directory. The "white pages" describe the company offering the service, like, name, address, contacts, etc. The "yellow pages" include industrial categories based on standard taxonomies the Standard Industrial Classification. The "green pages" describe the interface to the service in enough detail for someone to write an application to use the Web service.

3. What is WSDL?

Web Service Description Language (WSDL) defines an XML grammar for describing web services. This description includes details such as where to find the web service (its URL), what methods and properties that service supports, the data types and the protocols used to communicate with the service.

4. Describe Web Service (XML Web Service)?

A Web Service (XML Web Service) is a unit of code that can be activated using HTTP requests. Stated another way, a Web Service is an application component that can be remotely callable using standard Internet Protocols such as HTTP and XML. A major advantage of the Web services architecture is, it allows programs written in different languages on different platforms to communicate with each other in a standards-based way. Simply said, a Web service is a software service exposed on the Web through SOAP, described with a WSDL file and registered in UDDI.

5. Give examples of a Web Service?

o Information sources like stock quotes, weather forecasts, sports scores etc that could easily incorporate into applications

o Services that provide commonly needed functionality for other services. Example, user authentication, usage billing etc

o Services that integrate a business system with other partners

6. What is SOAP Protocol message contains?

A SOAP Protocol message contains four parts:

· An envelope

· Encoding Rules

· RPC representation (Convention)

· Protocol binding (optional)

an envelop that defines a framework for describing what is in a message and how to process it, a set of encoding rules for expressing instances of application-defined data types and a convention for representing remote procedure calls (RPC). In protocol binding, almost all SOAP implementations support it as it's the only standardized protocol for SOAP. The HTTP binding is optional.