Eclipse Day India 2015 - Rest with Java (jax rs) and jersey
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This document discusses REST APIs using Java (JAX-RS) and Jersey. It provides an overview of REST concepts and the JAX-RS and Jersey frameworks. It demonstrates how to create a basic Jersey project in Eclipse and implement CRUD operations. It also discusses using Swagger to generate documentation for RESTful APIs from JAX-RS annotations.
Eclipse Day India 2015 - Rest with Java (jax rs) and jersey
- 1. By NeeravArora (Cerner Healthcare Solutions Pvt Ltd.) & Kumaraswamy M (IBM) REST with Java (JAX-RS) and Jersey
- 2. Agenda Rest API concepts . Foundation . JAX-RS and Jersey . Setting up Jersey project in eclipse. JAX-RS annotations . CRUD app. Restful API’s with Swagger.
- 3. Rest API Concepts Services exposed to internet for programmatic access Users can be either producers or consumers or both Eg : api.twitter.com Data can be returned in the form of XML /JSON / etc Helps developers to parse data. Messages can be exchanged in any kind of HTTP method
- 4. Foundation Nouns (Resources) unconstrained i.e., http://example.com/employees/12345 Representations constrained i.e., XML Verbs constrained i.e., GET
- 5. Resources REST uses URI to identify resources . http://localhost/books/ http://localhost/books/ISBN-0011 http://localhost/books/ISBN-0011/authors http://localhost/classes http://localhost/classes/cs2650 http://localhost/classes/cs2650/students As you traverse the path from more generic to more specific, you are navigating the data .
- 6. Action/Verb /orders GET - list all orders POST - submit a new order /orders/{order-id} GET - get an order representation PUT - update an order DELETE - cancel an order /orders/average-sale GET - calculate average sale /customers GET - list all customers POST - create a new customer /customers/{cust-id} GET - get a customer representation DELETE- remove a customer /customers/{cust-id}/orders GET - get the orders of a customer
- 7. Representations (MediaType) XML <COURSE> <ID>CS2650</ID> <NAME>Distributed Multimedia Software</NAME> </COURSE> JSON {“course”: { “id”: “CS2650” “name”: “Distributed Multimedia Software” } }
- 8. Why it is called “REST” ?
- 9. JAX-RS Java API for RESTfulWeb Services . Provides support in creating web services according to the Representational StateTransfer (REST) architectural pattern . Uses annotations .
- 10. Jersey One of the libraries that implements JAX-RS , from Oracle. Other libraries in the market - * Apache CXF , an open sourceWeb service framework . * RESTeasy, JBoss 's implementation . * Restlet . * ApacheWink ,Apache Software Foundation Incubator . *WebSphereApplication Server from IBM. Choice of library doesn’t matter .
- 11. Big Picture
- 13. Your first Jersey project
- 14. Your first Jersey project (contd…)
- 15. http://repo1.maven.org/maven2/archetype-catalog.xml Your first Jersey project (contd…)
- 16. Your first Jersey project (contd…)
- 17. Your first Jersey project (contd…)
- 18. Your first Jersey project (contd…)
- 20. @Path Sets the path to base URL + /your_path.The base URL is based on your application name, the servlet and the URL pattern from the web.xml configuration file.
- 21. @GET, @PUT, @POST, @DELETE, ...
- 22. @Produces @Produces defines which MIME type is delivered by a method annotated with @GET. In the example text ("text/plain") is produced. Other examples would be "application/xml" or "application/json"
- 23. @PathParam Used to inject values from the URL into a method parameter.This way you inject, for example, the ID of a resource into the method to get the correct object.
- 24. @Consumes @Consumes defines which MIME type is consumed by this method.
- 25. CRUD App example (Model)
- 26. CRUD App example (Model)
- 27. CRUD App example (Database)
- 28. CRUD App example (Service)
- 30. RESTFul APIs with Swagger
- 31. What is Swagger and Why Swagger? • Simple representation of your RESTFul API • Declarative resource specification • JSON specification • Swagger UI to interact with the API in a sandbox UI • Why Jersey Client / JUNIT for your client or boss? • Developers and documentation… hahaha • Support your existing RESTFul API without change
- 32. Swagger Specification • Resource Listing • API Description Create Swagger Specification • Codgen - converts annotations in your code into swagger specification • Manually - writing the JSON by hand
- 35. References • http://www.vogella.com/tutorials/REST/article.html • https://jersey.java.net/documentation/latest/jaxrs- resources.html • https://github.com/koushikkothagal/messenger • http://swagger.io/specification/ • https://github.com/swagger-api/swagger-spec • https://github.com/swagger-api/swagger-core • http://petstore.swagger.io/