Restful Web Services Interview Questions

By Umesh Singh
Last update: 28 Jun 2020, 22 Questions
Web Services Interview questions

Web services are modular, self-contained, dynamic and distributed applications that can be published, described, invoked or located over the network to create processes, products and supply chains. These applications can be distributed web-based or local. All of the web services are developed on top of open standards such as HTTP, Java, HTML, TCP/IP, and XML. We will discuss a set of expert picked Restful Web Services Interview Questions with the most suitable answers further here. It is utilized for the machine to machine communication, specifically for transferring machine-readable files such as JSON and XML. Web services are used to communicate one programming language with another, so it’s a medium to achieve interoperability. Due to the high demand for web services, businesses from every niche globally are hiring web service professionals to support them optimally.

Advantages of Restful Web Services

  • Web services can expose the existing code functionality over the network so that other applications can use the similar feature of the program.
  • Can be used to make the application technology and platform-independent.
  • Web services allow various applications to communicate with each other and share services and data among themselves.
  • The use of standardization protocol in web services benefits businesses with a wide range of choices, cost reduction, and increased quality.
  • Web services utilize SOAP over HTTP protocol, so developers can work with existing low-cost internet for implementing web services.

Now, let’s discuss the most asked Restful Web Services Interview Questions for your acknowledgment, so you can ensure future success with your interviews.

Most Frequently Asked Web Services Interview questions

1. What are the difference between SOAP and REST Web Services?
1. It stands for Simple Object Access Protocol It stands for Representational State
2. It was a protocol and designed with a specification. It’s an Architectural style in which web services can be treated as a RESTful service.
3. Can’t make use of REST Can make use of SOAP
4. It uses service interfaces to expose its functionality to applications It uses Uniform Service locators to access to the components on the hardware device
2. What are the difference between JAX RPC and JAX WS?
1. Services based on JAX RPC uses the RPC programming model to invoke operations of a web service. RPC programming model invokes stubs located on the client to call methods on a remote server. Services based on JAX WS uses annotations to declare the endpoints of web service. The annotations use the requirement of deployment descriptors

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3. What do you mean by Web Service?

Web service is a standardized way to integrate web-based applications using SOAP, XML, UDDI and WSDL open standards over an internet protocol backbone. After this, developers can add web services to GUI to offer specific functionality to users.

4. Explain the advantages of Web Services.
Here are the advantages of web services:
  • Integration and interconnectivity with the legacy systems
  • Reduced operational costs
  • Faster system development
  • Better interfaces with clients
5. List the types of Web Services.
There are two types of web services:
  • SOAP web services: SOAP or Simple Object Access Protocol is based on transferring XML data as SOAP messages.
  • RESTful web services: Used to build web services that are maintainable, lightweight and scalable in nature.
6. What do you mean by SOAP?

Simple Object Access Protocol or SOAP is a messaging protocol which allows programs running on disparate operating systems to communicate using HTTP (Hypertext Transfer Protocol), and it's XML (Extensible Markup Language).

7. Explain the advantages & disadvantages of SOAP Web Services?
  • Simple to use
  • Platform and language independent
  • Firewall friendliness
  • Use of open standards
  • Universal interoperability
  • Extremely versatile
  • Highly flexible
  • helps to create payload format and extensible protocol
  • Extreme reliance on HTTP
  • Statelessness
  • Considerably slow
  • Serialization by value and not by reference
8. What do you mean by WSDL and why it is used?

WSDL or Web Services Description Language is an XML format for describing network services as a set of endpoints operating on messages containing procedure-oriented or document-oriented information. It allows developers to exchange info over a particular protocol between applications.

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9. What type of security is needed in web services? Explain
Web services require the following security:
  • Username/Password approach
  • X.509 approach: It identifies the user by a public key infrastructure
  • Kerberos
  • Digital Signature: XML signature to be used to protect data
  • Encryption: XML encryption to be used to protect data
10. What do you mean by UDDI?

Universal Description, Discovery, and Integration or also known as UDDI is an XML based standard used for describing, finding and publishing web services. It’s a specification for a distributed registry of web services and uses Web Service Definition Language (WSDL) to define interfaces of web services.

11. What is REST Web Services and also explain its benefits?

REpresentational State Transfer or REST web service is an architectural style for developing. It’s favorite due to its simplicity and fact that it builds upon existing features and systems of HTTP in order to achieve its objectives, as opposed to creating entirely new frameworks, technologies, and standards.

13. Explain the sun-jaxws.xml file?

The sun-jaxws.xml file is present in SOAP web services and helps in offering the endpoints details when JAX WS web services get deployed in a servlet container. Placed in WEB-INF directory, the sun-jaxws.xml file contains implementation class, endpoint name, meta information, and a URL pattern.

14. What do you mean by BEEP?

BEEP or Blocks Extensible Exchange Protocol is connection oriented internet protocol. SOAP messages inherit the additional service qualities from BEEP to maintain session context at the receiver and the sender.

15. What do you mean by SOA?

SOA or Service-Oriented Architecture is a collection of services. These services present in SOA communicate with each other and involve simple data passing or involve coordinating two or more services to perform an activity.

16. What is PKI?

Public Key Infrastructure or PKI is a framework of cybersecurity and encryption that protects communications between the server and users.

It works with two different cryptographic keys; a public key and a private key.

17. What is the difference between a SOA and a Web service?
S.no SOA Web Service
1. SOA or Service Oriented Architecture is an architectural concept focused on having different services communicating with each other to carry out a more significant function. A web service is a fundamental building block present in a Service Oriented Architecture. When multiple functions get combined, an application is created under an SOA

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20. what is JAXP used in Web Service?

In web service, JAXP is used to process XML data using applications written in the JAVA programming language. It works with a pluggability layer that allows you to plug in an implementation of the DOM or SAX APIs.

21. What do you mean by XML signature?

An XML signature is used to sign in recourse outside its containing document of XML. It’s also called the enveloped signature.