@requestparam 值 = 春季启动日期

Question

@Controller
@RequestMapping(value="/reservations")
public class ReservationController {
    private static final DateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");

    @Autowired
    private ReservationService reservationService;

    @RequestMapping(method = RequestMethod.GET)
    public String getReservation(@RequestParam(value="date", required=false) String dateString, Model model){
        Date date = null;
        if(dateString != null){
            try {
                date = DATE_FORMAT.parse(dateString);
            } catch (ParseException pe) {
                date = new Date();
            }
        }else{
            date = new Date();
        }
        List<RoomReservation> roomReservationList = this.reservationService.getRoomReservationsForDate(date);
        model.addAttribute("roomReservations", roomReservationList);
        return "reservations";
    }
}

我了解@RequestParam 注解用于将查询字符串的参数值绑定到控制器方法参数。例如，http://localhost:8080/reservations?date=2017-01-01。但是，value="date" 是从哪里来的呢？我在我的 html 页面中看不到任何值“日期”。

Answer 1

如果您将表单作为方法提交：“GET”（不是 POST）并且表单包含一个名为 date 的输入字段，那么提交此表单将触发此处理程序方法。