RESTFUL WEBSERVICESFernando Oliveira

Web Services

Internet

Web Service

Database

File System

REpresentational State Transfer

RESThttps://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm

"architectural style for distributed hypermedia systems” (Roy Thomas Fielding)

Implementation in accordance with REST

REST Constraints

Client-Server1

Stateless2

Isolated RequestsAll requests must to have all information needed to process the requested operation

Cache3

Uniform Interfaces4

“Any information that can be named can be a resource: a document or image, a temporal service, a collection of other resources, a non-virtual object (e.g. a person), and so on. A resource is a conceptual mapping to a set of entities, not the entity that corresponds to the mapping at any particular point in time.

Roy Fieldinghttps://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm

GET | POST http://www.example.com/customers

GET | PUT | DELETE http://www.example.com/customers/33245

Recursos

➤Removes a Resource

➤Updates an existing Resource

➤Creates a new Resource

➤Retrieves a Resource ➤CacheableGET

POST

PUT

DELETE

HATEOAS HATEOAS - Hipermedia As The Engine Of Application State

GET /items?q=macbook+air {

“results”: [ {

“_links”: [ { “rel”: “self”, “uri”: “/items/123“ }, { “rel”: “bids”, “uri”: “/items/123/bids“ }, { “rel”: “win”, “uri”: “/items/123/bids?q=win“ }

], “name”: “Macbook Air 2010 new”, “price”: “2300” }

] }

Layered System5

Code on Demand (Optional)6

The Optional code on demand constraint allows clients to request and execute code from servers.

This, in turn, allows the server to deploy new features to clients.

EXEMPLOS