Root Resource, Subresource, subresource locator

Reference(http://docs.oracle.com/javaee/6/tutorial/doc/gknav.html)
You can use a resource class to process only a part of the URI request. A root resource can then implement subresources that can process the remainder of the URI path.

A resource class method that is annotated with @Path is either a subresource method or a subresource locator:

• A subresource method is used to handle requests on a subresource of the corresponding resource.
  
• A subresource locator is used to locate subresources of the corresponding resource. 

 subresource method handles an HTTP request directly. The method must be annotated with a request method designator such as @GET or @POST, in addition to @Path. The method is invoked for request URIs that match a URI template created by concatenating the URI template of the resource class with the URI template of the method.


Example of a root resource and sub-resource

package test;

import javax.ws.rs.Path;
import javax.ws.rs.PathParam;

@Path("person")
public class PersonInfo {

	@Path("{pid}")
	public Person getPerson(@PathParam("pid") Integer pid){
		Person p = new Person();
		p.setFirstName("John");
		p.setLastName("Lennon");
		return p;
	}
}

import javax.ws.rs.GET;
import javax.ws.rs.Path;

public class Person {
	public String firstName;
	public String lastName;
	
	@GET
	@Path("firstname")
	public String getFirstName() {
		return firstName;
	}
	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}
	
	@GET
	@Path("lastname")
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

}