An overview of JAX-RS, Jersey, and REST API development

1. REST APIs
Overview and Jersey / JAX-RS Intro
Andy Pemberton
RJUG, May 2014

2. Background

3. Background
• Front-end guy
• Middleware Java guy
• Agilist, learner, polyglot
• Family guy 

4. REST in a Page
• Architectural Style – a set of constraints
• Nouns and Verbs
• HTTP-Based
• Roy Fielding – U. C. Irvine
– “Representational State Transfer”
• Not SOAP

5. Constraint: Nouns and Verbs

6. Constraint: Nouns and Verbs
• Nouns
– Your business model
• Account, Plan, Cat, Dog, Foo, Bar 
• Verbs
– HTTP-Defined (RFC-2616)
• GET, PUT, POST, DELETE
• TRACE, OPTIONS, HEAD
• PATCH

7. Examples
BAD
GET /fetch-accounts
GET /create-payment
POST /cancel-payment
GOOD
GET /accounts
POST /payment
DELETE /payments/{id}

8. Verbs
• GET (idempotent)
• PUT (idempotent)
• POST
• DELETE
• PATCH (draft)
• TRACE, OPTIONS, HEAD

9. Specs and Stuff
• JAX-RS – Java API for RESTful Web Services
– JSR-311 – JAX-RS 1.0
– JSR-339 – JAX-RS 2.0
• Dependency Injection
• Bean Validation
• Client API enhancements

10. Web & Mobile Friendly

11. Frameworks
• .NET – asp.net web API
• Others: Ruby, NodeJS, Scala, Python
• Java
– Glassfish (Oracle) – Jersey
– JBoss – RESTEasy
– Restlet
– Dropwizard

12. Jersey
• Oracle Reference Implementation
– JSR-311, JSR-339
• Extensions
• Examples Projects

13. OK - code time, but you got the idea…

14. Other Constraints
• Client-Server
• Hypermedia contracts (links, hrefs)
• Stateless

15. API Documentation
• wsdl 2.0, wadl
• apiary.io
• enunciate
• swagger
– Mashery I/O Docs

17. Swagger
• Swagger Core
– Annotations
– JAX-RS integration
– Schema generations
• Swagger UI

18. Advanced REST
• Partial representations
api.foobar.com/addresses?select=postalCode
• Resource linking / expansion
api.foobar.com/customers/1234?expand=accounts
• API Versioning

19. Fin
• References
– http://code.google.com/p/implementing-rest/wiki/ByLanguage
– https://stormpath.com/blog/linking-and-resource-expansion-
rest-api-tips/
– http://www.mashery.com/product/io-docs