RESTful Web services implemented using JAX-RS APIs provide responses as representations of a resource implemented by Java classes. A resource class is a class that uses JAX-RS annotations to implement a resource. For most RESTful Web services, there is a collection of resources that need to be accessed. The resource class' annotations provide information such as the URI of the resources and which HTTP verb each operation handles.
The JAX-RS APIs allow you to create two basic types of resources:
A root resource class is the entry point to a service's resource tree. It is decorated with the
@Pathannotation to define the base URI for the resources in the service.Sub-resources are accessed through the root resource. They are implemented by methods that are decorated with the
@Pathannotation. A sub-resource's@Pathannotation defines a URI relative to the base URI of a root resource.
Example 2.1 shows a simple resource class.
Example 2.1. Simple resource class
package demo.jaxrs.server; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.PathParam; @Path("/customerservice")public class CustomerService { public CustomerService() { } @GET
public Customer getCustomer(@QueryParam("id") String id) { ... } ... }
Two items make the class defined in Example 2.1 a resource class:
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