JAX-RS – REST in Java

Agenda Introduction Compare to SOAP Server code Client code Frameworks

Introduction Representational state transfer (Roy Fieding) Every URL represents an object or a state Who uses it? Amazon AWS (EC2, S3, etc.) Flickr Del.ici.ous Ebay CRUD by HTTP methods Create → POST Read → GET Update → PUT Delete → DELETE

Compare to SOAP REST advantages SOAP advantages Lightweight - not a lot of extra xml markup Human Readable Results Easy to build - no toolkits required SOAP advantages Easy to consume – sometimes Rigid - type checking, adheres to a contract Development tools

Server code Servlet API web.xml mapping doGet, doPost, doUpdate, doDelete Payload marshalling/unmarshalling Example JSR-311 (JAX-RS)

JAX-RS features Annotation based Deployment HTTP Data handling JAX-RS aware container javax.ws.rs.Application Servlet container Servlet Filter J2SE RuntimeDelegate.createEndpoint HTTP Data handling @Provider

JAX-RS HTTP Templated mapping and subresources MIME handling @Path MIME handling @Provides, @Consumes HTTP methods @GET, @POST, @UPDATE, @DELETE, @HEAD, @OPTIONS, @HttpMethod Caching evaluatePreconditions

JAX RS data handling URI templates Parameters Return values Resporse {name} {regex} Parameters @PathParam @QueryParam @FormParam @MatrixParam @HeaderParam @SessionParam @UriInfo @Encoded @CoockieParam @DefaultValue No annotation (entity) Return values Resporse GenericEntity Null Status 204 Entity (marshalled) Exceptions WebApplicationException Unchecked Filters, error pages Checked ServletException, WebServiceException @Provider extends ExceptionMapper

Entities Primitives String enum byte [], File, DataSource, etc. JAXB valueOf List, Set, SortedSet – not worked for me :-( @Provider MessageBodyReader MessageBodyWriter

Client code Old school – javascript, HttpClient REST oriented APIs No standard spec Framework offer good APIs org.jboss.resteasy.client.core com.sun.jersey.api.client

Frameworks Jboss resteasy Sun jersey CXF Axis2 Spring Others?

Q & A

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