JSON not generated in using Jersey

I'm using the latest version of Jersey to implement some REST sample services.

Do you have any clue why when I generate the following HTTP request using Fiddler,I get:

500 Internal Server Error

MessageBodyWriter not found for media type={application/json, q=1000}, type=class java.util.ArrayList, genericType=java.util.ArrayList<com.example.Todo>

HTTP request:

GET http://localhost:8080/RestProject/rest/todos/1 HTTP/1.1
Connection: close
Accept: application/json
User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/41.0.2272.101 Safari/537.36
Accept-Encoding: gzip, deflate, sdch
Accept-Language: it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4
Host: localhost:8080

That's the Rest method getting called:

 //This method is called if XML or JSON is requested  
  @GET  
  @Path("{id}")  
  @Produces({MediaType.APPLICATION_XML,MediaType.APPLICATION_JSON,MediaType.TEXT_XML})  
  public Todo getEntityXMLOrJSON(@PathParam("id") int id)  
  {
    Todo todo = new Todo();
    todo.setSummary("This is my first todo " + id);
    todo.setDescription("This is my first todo");
    return todo;
  }

When I request xml data everything works fine.

EDIT: