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Introduction to JAX-RS
The document provides an overview of REST (Representational State Transfer) and the Java API for RESTful Web Services (JAX-RS). It discusses REST constraints like using URIs, HTTP methods, and media types. It then demonstrates how to build a RESTful web service in Java using JAX-RS annotations for paths, parameters, responses, and caching.
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Presentation introduction and a brief overview of REST (Representational State Transfer) and its fundamental principles.
Explains key REST constraints, including URI usage, standard methods, media types, resource linking, session state avoidance, and caching.
Overview of JAX-RS as the Java API for building RESTful services, focusing on POJOs, annotations, and the importance of URLs and media types.
Demonstrates coding in JAX-RS, including defining resources, handling HTTP methods, and returning data in XML format.
Introduction to Media Types, context parameters like UriInfo, using cache control, and response handling based on user data.
Additional resources for further exploration of REST and JAX-RS, including links to Roy Fielding's dissertation and notable blogs.
Information on JAX-RS versions, their release dates, and various available implementations for developing RESTful applications.
Discusses statelessness advantages for better scalability, reliability, and resource reuse, with a focus on caching strategies to improve performance.
Introduction to JAX-RS
- 1. ______/\\\\\\\\\\\_____/\\\\\\\\\_____/\\\_______/\\\________________/\\\\\\\\\_________/\\\\\\\\\\\___ _____\/////\\\///____/\\\\\\\\\\\\\__\///\\\___/\\\/_______________/\\\///////\\\_____/\\\/////////\\\_ _________\/\\\______/\\\/////////\\\___\///\\\\\\/________________\/\\\_____\/\\\____\//\\\______\///__ _________\/\\\_____\/\\\_______\/\\\_____\//\\\\_______/\\\\\\\\__\/\\\\\\\\\\\/______\////\\\_________ _________\/\\\_____\/\\\\\\\\\\\\\\\______\/\\\\______\////////___\/\\\//////\\\_________\////\\\______ _________\/\\\_____\/\\\/////////\\\______/\\\\\\_________________\/\\\____\//\\\___________\////\\\___ __/\\\___\/\\\_____\/\\\_______\/\\\____/\\\////\\\_______________\/\\\_____\//\\\___/\\\______\//\\\__ _\//\\\\\\\\\______\/\\\_______\/\\\__/\\\/___\///\\\_____________\/\\\______\//\\\_\///\\\\\\\\\\\/___ __\/////////_______\///________\///__\///_______\///______________\///________\///____\///////////_____ ____/\\\\\\\\\______/\\\\\\\\\\\\\\\_____/\\\\\\\\\\\_____/\\\\\\\\\\\\\\\_ __/\\\///////\\\___\/\\\///////////____/\\\/////////\\\__\///////\\\/////__ _\/\\\_____\/\\\___\/\\\______________\//\\\______\///_________\/\\\_______ _\/\\\\\\\\\\\/____\/\\\\\\\\\\\_______\////\\\________________\/\\\_______ _\/\\\//////\\\____\/\\\///////___________\////\\\_____________\/\\\_______ _\/\\\____\//\\\___\/\\\_____________________\////\\\__________\/\\\_______ _\/\\\_____\//\\\__\/\\\______________/\\\______\//\\\_________\/\\\_______ _\/\\\______\//\\\_\/\\\\\\\\\\\\\\\_\///\\\\\\\\\\\/__________\/\\\_______ _\///________\///__\///////////////____\///////////____________\///________ with 2009-09-15 Andreas Bjärlestam
- 2. Andreas Bjärlestam mailto:andreas@bjarlestam.comhttp://andreas.bjarlestam.com http://twitter.com/bjarlestam
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- 4. Pragmatic explanation UseHTTP the way it was designed to be used Take advantage of the good things in HTTP By following a set of constraints
- 5. Constraints in RESTGive everything its own URI Communicate with a standard set of methods Communicate with Media Types Link your resources together Avoid session state Support caching * This is a very simplified version of the real REST constraints, for the real stuff read Roy Fieldings dissertation
- 6. JAX-RS (JSR 311)Java API for building RESTful services
- 7. JAX-RS Based onPOJOs with Annotations
- 8. JAX-RS Makes thedeveloper focus on URLs, HTTP methods and Media Types.
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- 10. @Path @Path( "location") public class LocationResouce { }
- 11. @GET, @PUT, @POST@Path( "location" ) public class LocationResouce { @GET @Produces( "application/xml" ) public String getLocation() { return "<location>I’m in Sweden</location>" ; } }
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- 13. @PathParam, @QueryParam @Path("location" ) public class LocationResouce { @GET @Path( "{user}" ) @Produces( "application/xml" ) public String getLocation(@PathParam( "user" ) String user) { return "<location>” + user + " is in Sweden</location>" ; } }
- 14. JAXB @Path( "location") public class LocationResouce { @GET @Path( "{user}" ) @Produces( "application/xml" ) public Location getLocation(@PathParam( "user" ) String user) { return new Location( "59.3" , "18" ); } }
- 15. JAXB @XmlRootElement public class Location { public String lattitude; public String longitude; public Date timestamp; . . . }
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- 17. @Produces and MediaTypes @Path( "location" ) public class LocationResouce { @GET @Path( "{user}" ) @Produces({ "application/xml", "application/json" }) public Location getLocation(@PathParam( "user" ) String user) { return new Location( "59.3" , "18" ); } }
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- 19. @Context, UriInfo andUriBuilder @Path( "location" ) public class LocationResouce { @Context UriInfo uriInfo; . . . @POST @Consumes( "application/x-www-form-urlencoded" ) public Response saveLocation(@FormParam( "user" ) String user) { locations.put (user, new Location( "59.3" , "18" )); UriBuilder uriBuilder = uriInfo .getAbsolutePathBuilder(); URI userUri = uriBuilder.path(user).build(); return Response.created(userUri).build(); } }
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- 21. Cache Control @GET@Path( "{user}" ) @Produces({ "application/xml", "application/json" }) public Response getLocation(@PathParam( "user" ) String user) { Location l = locations .get(user); CacheControl cc = new CacheControl(); cc.setMaxAge(500); Response.ResponseBuilder builder = Response.ok(l); builder.cacheControl(cc); return builder.build() ; }
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- 24. For the interestedRoy Fieldings PhD dissertation, see ch 5 http://www.ics.uci.edu/~fielding/pubs/dissertation/top.htm Roy Fieldings blog http://roy.gbiv.com/untangled/ Mark Hadleys blog http://weblogs.java.net/blog/mhadley/ Mark Nottinghams blog http://www.mnot.net Stefan Tilkovs blog http://www.innoq.com/blog/st/
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- 26. JAX-RS JSR 311Version 1.0 was finalized in september 2008 Version 1.1 is planned to be part of JEE6
- 27. JAX-RS Several implementationsavailable Sun Jersey JBoss RestEasy Restlets Apache CXF Triaxrs Apache WINK
- 28. Serendipity By givingeverything a URL, sticking to a Uniform Interface and linking your resources you make the chances of reuse in unexpected ways higher
- 29. Statelessness Better scalingNo session storage on server Any server in a cluster can handle any request The resources can safely be cached More reliable A client can safely re-send a request Better resource reuse The resources can safely be linked to
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- 31. Client Proxy CacheClient Client Server Proxy Cache Client Reverse Proxy Cache Client Cache Client Cache Client Cache Client Cache
- 32. “ The bestrequests are those that not even reach me.” - Anonymous overloaded Server
- 33. 50 requests/second =3000 requests/minute setting max-age=60 (seconds) can then save you 2999 requests
- 34. Caching GET canbe cached while POST can't (safely) Specify max-age Use max-age cache control header Split data according to freshness requirement Support conditional GET Get if modified since E-tags