@requestparam value = date spring boot

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"; 
    } 
} 

我知道@RequestParam注释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”来自哪里？我没有看到我的HTML页面中的任何值“日期”。

Answer 1

如果您提交表单为方法：“GET”（不是POST）并且表单包含名为date的输入字段，则提交此表单将会触发此处理程序方法。