The document outlines a general product direction intended for information purposes only and should not be relied upon for purchasing decisions. The development and release of any features remains at Oracle's sole discretion.

1. The following is intended to outline our general
product direction. It is intended for information
purposes only, and may not be incorporated into any
contract. It is not a commitment to deliver any
material, code, or functionality, and should not be
relied upon in making purchasing decisions.
The development, release, and timing of any
features or functionality described for Oracle’s
products remains at the sole discretion of Oracle.
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2. <Insert Picture Here>
Creating RESTful Web Services using JAX-RS
Ludovic Champenois
Architect GlassFish – NetBeans - Eclipse

3. Agenda
• REST and JAX-RS <Insert Picture Here>
• Deployment Options
• Demo
• Status
• Q&A
3

4. REST is an Architectural Style
• Set of constraints you apply to the architecture of a
distributed system to induce desirable properties
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5. RESTful Web Services
• Application of REST architectural style to services
that utilize Web standards:
• URIs, HTTP, MIME, HTML, XML, Atom, RDF, ...
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6. Java API for RESTful Web Services (JAX-RS)
• Standard annotation-driven API that aims to help
developers build RESTful Web services in Java™
• JSR 311
• Part of Java EE 6 now
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7. RESTful Application Cycle
Resources are identified by URIs
↓
Clients communicate with resources via requests using a
standard set of HTTP methods
↓
Requests and responses contain resource representations in
formats identified by media types
↓
Responses contain URIs that link to further resources
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8. Resources are identified by URIs
• http://example.com/widgets/foo
• http://example.com/customers/bar
• http://example.com/customers/bar/orders/2
• http://example.com/orders/101230/customer
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9. Resources are identified by URIs
• Resource == Java class POJO
• No required interfaces
• ID provided by @Path annotation
• Value is relative URI, base URI is provided by
deployment context or parent resource
• Embedded parameters for non-fixed parts of the URI
• Annotate class or “sub-resource locator” method
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10. Resources are identified by URIs
@Path("properties")
public class SystemProperties {
@GET
List<SystemProperty> getProperties(...) {...}
@Path("{name}")
SystemProperty getProperty(...) {...}
}
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11. Standard Set of Methods
Method Purpose
GET Read, possibly cached
POST Update or create without a known ID
PUT Update or create with a known ID
DELETE Remove
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12. Standard Set of Methods
• Annotate resource class methods with standard
method
– @GET, @PUT, @POST, @DELETE, @HEAD
• @HttpMethod meta-annotation allows extensions,
e.g. WebDAV
• JAX-RS routes request to appropriate resource class
and method
• Flexible method signatures, annotations on
parameters specify mapping from request
• Return value mapped to response
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13. Standard Set of Methods
@Path("properties/{name}")
public class SystemProperty {
@GET
Property get(@PathParam("name") String name)
{...}
@PUT
Property set(@PathParam("name") String name,
String value) {...}
}
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14. Resource Representations
• Representation format identified by media type. E.g.:
– XML - application/properties+xml
– JSON - application/properties+json
– (X)HTML+microformats - application/xhtml+xml
– JAX-RS automates content negotiation
– GET /foo
• Accept: application/properties+json
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15. Resource Representations
Static and dynamic content negotiation
• Annotate methods or classes with static capabilities
– @Produces, @Consumes
• Use Variant, VariantListBuilder and
Request.selectVariant for dynamic capabilities
• Also supports language and encoding
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16. Resource Representations
@GET
@Produces("application/properties+xml")
Property getXml(@PathParam("name") String name) {
...
}
@GET
@Produces("text/plain")
String getText(@PathParam("name") String name) {
...
}
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17. Responses Contain Links
HTTP/1.1 201 Created
Date: Wed, 08 Dec 2010 16:41:58 GMT
Server: Apache/1.3.6
Location: http://example.com/properties/foo
Content-Type: application/order+xml
Content-Length: 184
<property self="http://example.com/properties/foo">
<parent ref="http://example.com/properties/bar"/>
<name>Foo</name>
<value>1</value>
</order>
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18. Responses Contain Links
• UriInfo provides information about deployment
context, the request URI and the route to the resource
• UriBuilder provides facilities to easily construct URIs
for resources
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19. Responses Contain Links
@Context UriInfo i;
SystemProperty p = ...
UriBuilder b = i.getBaseUriBuilder();
URI u = b.path(SystemProperties.class)
.path(p.getName()).build();
List<URI> ancestors = i.getMatchedURIs();
URI parent = ancestors.get(1);
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20. Agenda
• REST and JAX-RS <Insert Picture Here>
• Deployment Options
• Demo
• Status
• Q&A
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21. Java SE Deployment
• RuntimeDelegate is used to create instances of a
desired endpoint class
• Application supplies configuration information
– List of resource classes and providers as subclass of
Application
• Implementations can support any Java type
– Jersey supports Grizzly and the LW HTTP server in Sun's
JDK.
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22. Example Java SE Deployment
Application app = ...
RuntimeDelegate rd =
RuntimeDelegate.getInstance();
Adapter a = rd.createEndpoint(app,
Adapter.class);
SelectorThread st = GrizzlyServerFactory.create(
“http://127.0.0.1:8084/”, a);
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23. Servlet
• JAX-RS application packaged in WAR like a servlet
• For JAX-RS aware containers
– web.xml can point to Application subclass
• For non-JAX-RS aware containers
– web.xml points to implementation-specific Servlet; and
– an init-param identifies the Application subclass
• Resource classes and providers can access Servlet
request, context, config and response via injection
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24. Java EE
• Resource class can be an EJB session or singleton bean
or CDI Beans
• Providers can be an EJB stateless session or singleton
bean
• JAX-RS annotations on local interface or no-interface
bean
• Full access to facilities of native component model, e.g.
resource injection
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25. EJB with JAX-RS
@Path("stateless-bean")
@Stateless
public class StatelessResource { … }
@Path("singleton-bean")
@Singleton
public class SingletonResource { … }
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26. CDI and JAX-RS
• General CDI requirement: beans.xml needs to be declared to
enable CDI managed beans
– e.g. empty WEB-INF/beans.xml in war
• Root resource classes need to be annotated with a CDI scope
@Path("request-scoped")
@RequestScoped
public class RequestScopedResource { … }
@Path("application-scoped")
@ApplicationScoped
public class ApplicationScopedResource { … }
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27. Servlet 3.0 and JAX-RS
• No WEB-INF/web.xml for simple deployments
• Use extension of javax.ws.rs.Application and
@javax.ws.rs.ApplicationPath
@ApplicationPath("resources”)
public class MyApp extends Application { ... }
• Use WEB-INF/web.xml for portable deployments
<web-app version="3.0">
<servlet>
<servlet-name>Jersey Web
Application</servlet-name>
<servlet-class>...MyApp</servlet-class>
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28. Agenda
• REST and JAX-RS <Insert Picture Here>
• Deployment Options
• Demo
– Matching URLs,
– Consuming POST Requests (@POST, @FormParam)
– GlassFish Admin Backend: A REST Application
• Status
• Q&A
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29. Agenda
• REST and JAX-RS <Insert Picture Here>
• Deployment Options
• Demo
• Status
• Q&A
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30. Status
• JAX-RS 1.0: 18th October 2008
• JAX-RS 1.1: 23rd November 2009
– Aligned with Java EE 6, but not in the Web profile!
• JAX-RS 2.0: Future<?>
– Draft JSR 12th November 2010
– Like to submit to JCP in December or early next year
– http://bit.ly/bkXtay
• Implementations
– Apache CXF, Apache Wink, eXo, Jersey, RESTEasy, Restlet,
Triaxrs
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31. Agenda
• REST and JAX-RS <Insert Picture Here>
• Deployment Options
• Demo
• Status
• Q&A
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