Restful Web Services Interview Questions and Answers
Q1. What are RESTful webservices?
Ans: Web services based on REST Architecture are called RESTful net offerings. These net services use HTTP strategies to enforce the concept of REST structure. A RESTful web carrier typically defines a URI, Uniform Resource Identifier a provider, affords useful resource representation along with JSON and set of HTTP Methods.
Q2. What is differences between RESTful internet services and SOAP internet services ?
Ans: Though both RESTful Web Services and SOAP internet service can perform go platform they are architecturally extraordinary to each different, here is a number of variations between REST and SOAP:
1. REST is extra simple and clean to apply than SOAP
2. REST uses HTTP protocol for producing or eating web offerings even as SOAP uses XML.
3. REST is light-weight compared to SOAP and desired choice in cell gadgets and PDA's.
4. REST supports exceptional layout like textual content, JSON and XML at the same time as SOAP handiest assist XML.
Five. REST net services call can be cached to enhance overall performance.
Q3. What is Resource in REST framework ?
Ans: it represent a "useful resource" in REST architecture. On RESTLET API it has life cycle methods like init(), handle() and launch() and includes a Context, Request and Response corresponding to particular goal aid. This is now deprecated over ServerResource elegance and you need to use that. See Restlet documentation for more info.
Q4. What are critical capabilities of Restful net services?
Ans: Some crucial features of Restful web offerings are:
Resource identification via URI:Resources are diagnosed by using their URIs (usually hyperlinks on net). So, a client can at once get admission to a RESTful Web Services the usage of the URIs of the assets (equal as you positioned a internet site cope with within the browser’s address bar and get some representation as reaction).
Uniform interface: Resources are manipulated using a fixed set of 4 create, study, update, delete operations: PUT, GET, POST, and DELETE.
Client-Server: A clear separation worries is the cause behind this constraint. Separating concerns between the Client and Server facilitates improve portability within the Client and Scalability of the server additives.
Stateless: each request from purchaser to server need to incorporate all of the data important to apprehend the request, and can't take benefit of any stored context on the server.
Cache: to enhance community efficiency responses should be capable of being labeled as cacheable or non-cacheable.
Named resources – the gadget is made from assets which can be named the use of a URL.
Interconnected aid representations – the representations of the resources are interconnected the use of URLs, thereby allowing a client to development from one nation to every other.
Layered additives – intermediaries, inclusive of proxy servers, cache servers, gateways, and so forth, can be inserted between customers and resources to assist performance, protection, and so on.
Self-descriptive messages: Resources are decoupled from their representation in order that their content material may be accessed in a variety of formats, inclusive of HTML, XML, undeniable text, PDF, JPEG, JSON, and others
Q5. What are HTTP techniques that may be used in Restful internet offerings?
Ans: RESTful internet services use HTTP protocol techniques for the operations they perform.
Some important Methods are:
GET : It defines a analyzing access of the aid without facet-results.This operation is idempotent i.E.They may be applied a couple of instances without converting the end result
PUT : It is typically used for updating resource. It ought to also be idempotent.
DELETE : It gets rid of the resources. The operations are idempotent i.E. They could get repeated with out leading to exceptional consequences.
POST : It is used for growing a new useful resource. It isn't idempotent.
Q6. What are the tools used for growing RESTFull internet offerings ?
Q7. What do you mean with the aid of Idempotent and which HTTP techniques are idempotent?
Ans: Idempotent method result of a couple of successful request will no longer trade state of useful resource after preliminary utility
For instance : Delete is idempotent technique due to the fact whilst you first time use delete, it's going to delete the aid (initial utility) but after that, all other request will have no end result because useful resource is already deleted. Get, placed and delete are HTTP Idempotent techniques.
Q8. What are differences among Post and Put Http strategies?
POST :It is used for creating a new aid. It isn't idempotent.
PUT : It is generally used for updating aid. It is idempotent.
Idempotent approach result of a couple of a hit request will now not exchange kingdom of useful resource after preliminary application
Q9. What is statelessness in RESTful Webservices?
Ans: As per REST structure, a RESTful web service need to now not maintain a purchaser nation on server. This restriction is called statelessness. It is obligation of the client to pass its context to server and then server can save this context to system purchaser's similarly request. For example, consultation maintained through server is diagnosed by using consultation identifier surpassed by the purchaser.
Q10. What are the advantages of statelessness in RESTful Webservices?
Ans: Following are the blessings of statelessness in RESTful net services
Web offerings can deal with each approach request independently. Web services need not to preserve patron's previous interactions. It simplifies software layout. As HTTP is itself a statelessness protocol, RESTful Web services work seamlessly with HTTP protocol.
Q11. What are the risks of statelessness in RESTful Webservices?
Ans: Following is the drawback of statelessness in RESTful web services ? Web offerings want to get greater statistics in every request and then interpret to get the consumer's country in case purchaser interactions are to be taken care of.
Q12. What are the first-rate practices for caching?
Q13. How to display custom blunders pages the use of RestFull web services ?
Ans: In order to personalize errors you need to extend StatusService and implement getRepresentation(Status, Request, Response) method with your custom code now assign instance of your CustomStatusService to appropriate "statusService assets".
Q14. What occurs if RestFull assets are accessed by means of a couple of clients ? Do you want to make it thread-secure?
Ans: Since a brand new Resource example is created for every incoming Request there is no want to make it thread-safe or upload synchronization. More than one purchaser can properly get right of entry to RestFull resources simultaneously.
That’s all on REST interview questions , I will upload couple of greater REST Interview questions whenever I got them from my pal circle.
Q15. What is JAX-RS?
Ans: Java API for RESTful Web Services (JAX-RS), is a hard and fast if APIs to developer REST carrier. JAX-RS is part of the Java EE6, and make developers to increase REST web software without difficulty.
Q16. What are REST frameworks that you are privy to and which may be used to create Restful webservices?
Ans: There are more than one Rest framework that can be used to create Restful net offerings inclusive of
Spring Rest webservices
Q17. What is addressing in RESTful webservices?
Ans: Addressing refers to finding a resource or a couple of resources mendacity at the server. It has similarities to find a postal address of a person.
Q18. What are important constraints for a RESTful Web Service?
Ans: The 5 crucial constraints for RESTful Web Service are
Client - Server : There have to be a carrier manufacturer and a provider patron.
The interface (URL) is uniform and exposing resources. Interface makes use of nouns (now not moves)
The provider is stateless. Even if the service is known as 10 instances, the result must be the identical.
The service result should be Cacheable. HTTP cache, for example.
Service must expect a Layered structure. Client must now not anticipate direct connection to server - it is probably getting information from a center layer - cache.
Q19. What have to be the reason of HEAD method of RESTful net offerings?
Ans: It ought to go back most effective HTTP Header, no Body and need to be read most effective.
Q20. Which type of Webservices strategies are to be read handiest?
Ans: GET operations are examine simplest and are secure.