Web Services Interview Questions – Set 02

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What tools are used to test web services?

The tools used to test web services are:

  • SoapUI tool for testing SOAP and RESTful web services
  • Poster for firefox browser
  • Postman extension for Chrome

Which language does UDDI use?

The UDDI uses the language known as WSDL (Web Service Description Language).

Explain different HTTP methods supported by RESTful web services?

Enlisted below are some common HTTP methods along with their functions that are supported by RESTful web services.

  • GET: Read-only access to the resource.
  • PUT: Creation of new resource.
  • DELETE: Removal of a resource.
  • POST: Update of an existing resource.
  • OPTIONS: Get supported operations on the resource.
  • HEAD: Returns HTTP header only, nobody.

What is the usage of Service Transport Layer in Web service protocol stack?

The Service Transport Layer is used to transport messages between applications.

This layer includes Hypertext Transport Protocol (HTTP), Simple Mail Transfer Protocol (SMTP), File Transfer Protocol (FTP), and newer protocols like Blocks Extensible Exchange Protocol (BEEP).

What are the main features of SOAP?

The following list specifies the features of SOAP:

  • SOAP is a communication protocol.
  • SOAP communicates between applications.
  • SOAP is a format for sending messages.
  • SOAP is designed to communicate via Internet.
  • SOAP is platform independent.
  • SOAP is language independent.
  • SOAP is simple and extensible.
  • SOAP allows you to get around firewalls.
  • SOAP developed as a W3C standard.

Explain web service protocol stack and its layers?

The web services consist of four layers, as mentioned below:

Service transport:

This layer is the first layer in the web services protocol stack used in transporting XML files between various clients applications. Protocols used in the layer is as follows:

  • HTTP (Hypertext transfer protocol)
  • SMTP (Simple Mail Transfer Protocol)
  • FTP (File Transfer Protocol)
  • BEEP (Block Extensible Exchange Protocol)

XML Messaging:

This layer is the second layer in the web services protocol stack based on XML model where messages are encoded in common XML format which can be understandable to other client applications. This layer includes the following protocols:

  • XML – RPC
  • SOAP (Simple Object Access Protocol)

Service Description:

This layer provides the service description to the public interface like the location of web service, Available functions, And the data types for XML messaging. This layer only includes one language:

  • WSDL: WSDL stands for Web Service Description Language.

Service Discovery:

This layer in the Web Services protocol stack is used to publish or finding web services over the web. This layer includes:

UDDI (Universal Description, Discovery, and integration).

What is the advantage of XML in web service?

In Web service, an XML is used to tag the data, format the data.

What are the steps involved in accessing a web service?

These are the steps involved in accessing a web service:

  1. Client application bundled the information and into a SOAP message.
  2. SOAP message sends to the server as a body of Hyper-Text markup language using POST method.
  3. Web service unpacks the SOAP message and converts it into a command understandable by the application.
  4. Application processes the information and in turn bundled the info and send it back to the client as a SOAP message.
  5. A Client then unpacks the SOAP message to obtain the results.

What are the advantages of web services?

These are some of the important advantages of web services:

Interoperability: With the help of web services, an application can communicate with other application developed in any language.
Reusability: We can expose the web service so that other applications can use it.
Modularity: With the help of web service, we can create a service for a specific task such as tax calculation.
A Standard protocol for every application program: Web services use standard protocol so that all the client applications written in different languages can understand it. This Standard protocol helps in achieving cross-platform.
Cheaper cost for communication: Web services uses SOAP over HTTP so that anybody can use existing internet for using web services.

What is the usage of Service Description layer in Web Service Protocol Stack?

The Service Description layer is used to describe the public interface to a specific web service. Currently, service description is handled via the Web Service Description Language (WSDL).