Spring MVC中用一个独立的私有方法指定@ModelAttribute属性。代码来源于：http://spring.io/guides/tutorials/web/5/

SpringMvcModelAttributeSample.java

@Controller
@RequestMapping("/order/{orderId}")
public class OrderStatusController {

    private static final Logger LOG = LoggerFactory
            .getLogger(OrderStatusController.class);

    @Autowired
    private OrderService orderService;

    @RequestMapping(method = RequestMethod.GET)
    public String orderStatus(@ModelAttribute("orderStatus") OrderStatus orderStatus) {
        LOG.debug("Get order status for order id {} customer {}", orderStatus.getOrderId(), orderStatus.getName());
        return "/order";
    }

    @ModelAttribute("orderStatus")
    private OrderStatus getOrderStatus(@PathVariable("orderId") String orderId) {
        OrderStatus status = orderService.requestOrderStatus(orderId);
        return status;
    }
}