ProductResource.java

package com.sun.jersey.samples.hypermedia.server.controller;

import com.sun.jersey.core.hypermedia.Action;
import com.sun.jersey.core.hypermedia.ContextualActionSet;
import com.sun.jersey.core.hypermedia.HypermediaController;
import com.sun.jersey.core.hypermedia.HypermediaController.LinkType;
import com.sun.jersey.samples.hypermedia.server.db.DB;
import com.sun.jersey.samples.hypermedia.server.model.*;
import java.util.HashSet;
import java.util.Set;
import javax.ws.rs.Consumes;

import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;

import static com.sun.jersey.samples.hypermedia.server.model.Product.Status.*;

/**
 * ProductResource class.
 *
 * @author Santiago.PericasGeertsen@sun.com
 */
@Path("/products/{id}")
@HypermediaController(
    model=Product.class,
    linkType=LinkType.LINK_HEADERS
    )

public class ProductResource {

    private Product product;

    public ProductResource(@PathParam("id") String id) {
        product = DB.products.get(id);
        if (product == null) {
            throw new WebApplicationException(404);     // not found
        }
    }

    @GET
    @Produces("application/xml")
    public Product getProduct(@PathParam("id") String id) {
        return product;
    }

    @PUT
    @Consumes("application/xml")
    public void putProduct(@PathParam("id") String id, Product product) {
        assert id.equals(product.getId());
        if (product.getQuantity() <= 0) {
            assert product.getStatus() == OUT_OF_STOCK;
        } else {
            assert product.getStatus() == IN_STOCK;
        }
        this.product = product;
        DB.products.put(id, product);
    }

    // -- Actions and ActionSets ------------------------------------
    //
    // Set a products's state as DISCONTINUED.
    // For simplicity, this action is implemented by updating the
    // product's status. Note that this could be done also using
    // @PUT. In general, this action may involve several steps (a
    // workflow) that cannot be easily translated into a single @PUT
    // action by the client.
    //

    @GET
    @Action("refresh") @Path("refresh")
    @Produces("application/xml")
    public Product refresh(@PathParam("id") String id) {
        return getProduct(id);
    }

    @PUT
    @Action("update") @Path("update")
    @Consumes("application/xml")
    public void update(@PathParam("id") String id, Product p) {
        putProduct(id, p);
    }

    @POST
    @Action("discontinue") @Path("discontinue")
    public void discontinue() {
        product.setStatus(DISCONTINUED);
    }

    /**
     * Product Version 1.
     */
    @ContextualActionSet
    public Set<String> getContextualActionSet() {
        Set<String> result = new HashSet<String>();
        result.add("refresh");
        result.add("update");    
        switch (product.getStatus()) {
            case OUT_OF_STOCK:
                result.add("discontinue");      // @Action's value
                break;
        }
        return result;
    }

}