Passing Parameter to Rest Client - rest

Question

In my gwt application, I've implemented this method:
#Service("carService")
#Path("/cars")
#Scope("request")
public class CarServiceImpl implements CarService {
#Autowired
private CarDAO carDAO;
#Override
#GET #Path("{type}/{start}/{end}")
#Produces({MediaType.APPLICATION_XML})
public List<Car> findByType(#PathParam("type") CarType type,
#PathParam("start") Date start,
#PathParam("end") Date end) {
return carDAO.findByType(type, start, end);
}
where findByType is a method in the carDAO asking to databases (in a peer-to-peer architecture) for available cars to rent.
Now I have to implement its rest client and I have:
package it.unibo.ronf.server.rest;
import java.util.Date;
import java.util.List;
import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.GenericType;
import com.sun.jersey.api.client.UniformInterfaceException;
import com.sun.jersey.api.client.WebResource;
import it.unibo.ronf.shared.entities.Car;
import it.unibo.ronf.shared.entities.CarType;
public class ClientRestCars {
public List<Car> findAvailableCar(CarType type, Date start, Date end) {
Client client = Client.create();
WebResource webResource = client
.resource("http://localhost:8080/RONF/rest/cars");
}
}
and I don't know how to go on, how to pass the parameters to the url and get the list of cars as results.
Can help?

Answer 1

If you don't have a framework to send your request, you should look at restygwt. It allows to create such requests in this way :
#PUT
#Path("{type}/{start}/{end}")
public void updateOrder(#PathParam("type") CarType carType,
#PathParam("start") Date start,
#PathParam("end") Date end,
MethodCallback<OrderConfirmation> callback);
Note : If you are using gwtp, you should note that they will soon provide this type of interface out-of-the-box.
Here is a quick example but you still should read the user guide
First, create a service (an interface which extends RestService):
#Path("/test/method")
public interface CarService extends RestService {
/*
* With #PathParam, you can specify the name of the attribute in the request.
* Without PathParam, the name of the attribute takes the name of the argument.
* The parameter type T of MethodCallBack<T> is the type you expect in the success method of the callback (see above)
*/
#GET
public void get(CarType carType,#PathParam("start")Date myStartDateWithASillyName, Date end,MethodCallback<List<Car>> callback);
/*
* Another method just to show that you are not limited to one...
* Here, the request have car parameter and is intended to save a car.
* As REST norms expect in this case, the resulting car is returned from server (with potentially the id updated after insert in database)
*/
#POST
public void post(Car car,MethodCallback<Car> callback);
}
Now, from anywhere in your code, you can call your service like this:
CarService service = GWT.create(CarService.class);
service.get(carType,dateFrom,dateTo,new MethodCallback<List<Car>>() {
/*
*This method is called if a problems occurs (server not reachable, 404,403 etc)
*/
public void onFailure(Method method, Throwable exception) {
Window.alert("Error x: " + exception);
}
/*
* In case of success, this method is called and you obtain
* the expected List<Car> as the response parameter
*/
public void onSuccess(Method method, List<Car> response) {
...
}
});