web services testing

What is a web service?

Web service is used to communicate or exchange data between multiple application and platforms. 

 What is the use of web service?

Exposing the existing function on to network:

A Web service is a unit of managed code that can be remotely invoked using HTTP, that is, it can be activated using HTTP requests. So, Web Services allows you to expose the functionality of your existing code over the network. Once it is exposed on the network, other application can use the functionality of your program.

Connecting Different Applications i.e. Interoperability:

Web Services allows different applications to talk to each other and share data and services among themselves. Other applications can also use the services of the web services. For example VB or .NET application can talk to java web services and vice versa. So, Web services are used to make the application platform and technology independent.

Standardized Protocol:

Web Services uses standardized industry standard protocol for the communication. All the four layers (Service Transport, XML Messaging, Service Description and Service Discovery layers) use the well defined protocol in the Web Services protocol stack. This standardization of protocol stack gives the business many advantages like wide range of choices, reduction in the cost due to competition and increase in the quality. 

Low Cost of communication:

Web Services uses SOAP over HTTP protocol for the communication, so you can use your existing low cost internet for implementing Web Services. This solution is much less costly compared to proprietary solutions like EDI/B2B. Beside SOAP over HTTP, Web Services can also be implemented on other reliable transport mechanisms like FTP etc.

What is WSDL? (Source: W3Schools)

WSDL stands for Web Services Description Language.  WSDL is a language for describing web services and how to access them. WSDL is written in XML.

What is UDDI?

UDDI is a platform-independent framework for describing services, discovering businesses, and integrating business services by using the Internet.

• UDDI stands for Universal Description, Discovery and Integration
• 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
• UDDI is built into the Microsoft .NET platform

What is SOAP?

SOAP stands for Simple Object Access Protocol. SOAP is a protocol for accessing web services. SOAP is based on XML.

Why SOAP?

It is important for application development to allow Internet communication between programs.
Today's applications communicate using Remote Procedure Calls (RPC) between objects like DCOM and CORBA, but HTTP was not designed for this. RPC represents a compatibility and security problem; firewalls and proxy servers will normally block this kind of traffic.
A better way to communicate between applications is over HTTP, because HTTP is supported by all Internet browsers and servers. SOAP was created to accomplish this.
SOAP provides a way to communicate between applications running on different operating systems, with different technologies and programming languages.

What is synchronous web service?

-          It gets response immediately.

What is asynchronous web service?

-Response will be sent when the service is available.

What is end point in web services?

End point is IP address of the servers where web services are running.