Spring MVC REST 实现返回不同状态的控制器，代码来自：http://spring.io/guides/tutorials/rest/2/

OrderCommandsController.java

@RequestMapping(method = RequestMethod.DELETE, value = "/{id}")
public ResponseEntity<Order> cancelOrder(@PathVariable String id) {

    OrderDeletedEvent orderDeleted = orderService.deleteOrder(new DeleteOrderEvent(UUID.fromString(id)));

    if (!orderDeleted.isEntityFound()) {
        return new ResponseEntity<Order>(HttpStatus.NOT_FOUND);
    }

    Order order = Order.fromOrderDetails(orderDeleted.getDetails());

    if (orderDeleted.isDeletionCompleted()) {
        return new ResponseEntity<Order>(order, HttpStatus.OK);
    }

    return new ResponseEntity<Order>(order, HttpStatus.FORBIDDEN);
}