Examples for Chapter 10 - RESTful Java with JAX-RS 2.0 - page 308

The addCancelHeader() method creates a Link object for the cancel relationship using a
URL generated from UriInfo.getAbsolutePathBuilder() .

@HEAD
@Path ( "{id}" )
@Produces ( "application/xml" )
public public Response getOrderHeaders ( @PathParam ( "id" ) int int id ,

@Context UriInfo uriInfo )

{

Order order = orderDB . get ( id );
iif ( order == null null )

{

throw throw new new WebApplicationException ( Response . Status . NOT_FOUND );

}
Response . ResponseBuilder builder = Response . ok ();
builder . type ( "application/xml" );
iif (! order . isCancelled ()) addCancelHeader ( uriInfo , builder );
return

return builder . build ();

}

The getOrderHeaders() method processes HTTP HEAD /orders/{id} requests. This is a
convenience operation for HTTP clients that want the link relationships published by the re-
source but don't want to have to parse an XML document to get this information. Here, the
getOrderHeaders() method returns the cancel Link header with an empty response body:

@POST
@Path ( "{id}/cancel" )
public public void void cancelOrder ( @PathParam ( "id" ) int int id )

{

Order order = orderDB . get ( id );
iif ( order == null

null )

{

throw throw new new WebApplicationException ( Response . Status . NOT_FOUND );

}
order . setCancelled ( true

true );

}

Users can cancel an order by posting an empty message to /orders/{id}/cancel . The can-
celOrder() method handles these requests and simply looks up the Order in the database
and sets its state to cancelled.

@GET
@Produces ( "application/xml" )
@Formatted
public public Response getOrders ( @QueryParam ( "start" ) int int start ,