What is a Web Service

Web Services generally uses HTTP or HTTPS protocol over the application layer of computer network where one application transfer data or send requests as XML or JSON and receives the response which is processed by the client application as a web service irrespective of underlying software platform, architecture and technology.

Web Services Testing basically involves

  1. Understand the WSDL file
  2. Determine the operations that particular web service provides
  3. Determine the XML request format which we need to send
  4. Determine the response XML format
  5. Using a tool or writing code to send request and validate the response

Web Services Components are:

All the standard web services work using the following components

  1. SOAP (Simple Object Access Protocol)
  2. UDDI (Universal Description, Discovery and Integration)
  3. WSDL (Web Services Description Language)

Web service Operation:

Web service enables communication among various applications installed on different devices by using open standards as discussed below:

  1. HTML page to send the request and render the received the response via HTTP/HTTPS protocol.
  2. XML to tag the request and response data.
  3. SOAP to transfer a message over the web.
  4. WSDL to describe the availability of web service.

Benefits of Web Services:

  1. Performance and reliability of the SOA are improved
  2. Eases testing of both SOA-based and REST API-based web services
  3. Test execution of web services in a cloud environment are also Supported
  4. Reduces Testing efforts over regression cycles
  5. Ensures 100% Functional Test coverage

The purpose of Web Service testing is to verify that all of the Web Service APIs published by your application operate as expected. Web Service API testing requires that you test using all the expected data formats and input parameters.

There are two broad classes of web service:

  1. SOAP (Simple Object Access Protocol)
  2. REST (Representational State Transfer architecture)

SOAP: It is a standard protocol defined by the W3C Standard for sending and receiving web service requests and responses.

SOAP uses the XML format to send and receive the request and hence the data is platform independent data. SOAP messages are exchanged between the provider applications and receiving application within the SOAP envelops

As SOAP uses the simple http transport protocol, its messages are not got blocked by the firewalls.

Rest: It is an architecture that generally runs over HTTP. The REST style emphasizes the interactions between clients and services, which are enhanced by having a limited number of operations. REST is an alternative to SOAP (Simple Object Access Protocol) and instead of using XML for request REST uses simple URL in some cases.