【发布时间】：2012-02-14 07:46:41
【问题描述】：
我是面向对象设计的新手，并且仍在学习它的过程中。 我为火车预订系统设计了一个类，但我不确定如何为主要预订类建模。
这就是我的设计的样子：
public class Station {
private int stationID;
private String stationName;
// Getters and Setters
}
public class Train {
private int trainID;
private String trainName;
private Map<Station, Double> trainStationsWithFares;
public Train(int ID, String trainName, Station[] stations) {
// Initialize ID and name and create a hashmap with all stations and
// zero fare initially for all stations.
....
trainStationsWithFares = new HashMap<Station, Double>();
for(Station s : stations) trainStationsWithFares.put(s, new Double(0.0));
}
// Getters and Setters (including methods to add new stations with fares and
// update fares of existing stations
}
public class Passenger {
private String Name;
private int id;
private int age;
private static final enum { Male, Female } gender;
}
public class TicketDetails {
private Train t;
private Station from;
private Station to;
private Passenger passenger;
// Getters and Setters
}
public class TrainTicket {
private int ID;
private TicketDetails ticketDetails;
private Double fare;
public TrainTicket(TicketDetails ticketDetails)
throws InvalidTrainException, InvalidFromStationException,
InvalidToStationException {
...
calculateFare();
}
// Calculates fare based on Train and from and to Stations and taxes, etc.
private void calculateFare() {
this.fare = ...
}
}
// Assuming card payment only for online reservation system for simplicity.
// Design can be modified and enhanced suitably.
public class PaymentDetails {
private String cardNumber;
private String cardExpirationMonth;
private String cardExpirationYear;
private String cardCVV;
// Getters and Setters
}
我的问题：我的预订舱位应该像这样吗？
如果是这样，该类中的方法将如何访问TrainTicket、PaymentDetails等其他类的对象？
public abstract class ReservationSystem {
// Purchase train ticket by providing ticket details and payment details.
public abstract TrainTicket purchaseTicket(TicketDetails ticketDetails,
PaymentDetails paymentDetails);
// Cancel existing train ticket by providing ticket reference and payment details
// for cancellation charges.
public abstract boolean cancelTicket(TrainTicket tt, PaymentDetails details);
// Modify existing train ticket by providing existing ticket reference,new ticket
// details and payment details for any additional charge or modify charges.
public abstract TrainTicket modifyTicket(TrainTicket existingTicket,
TicketDetails newTicketDetails, PaymentDetails paymentDetails) {
}
}
还是应该是这样的：
public class ReservationSystem{
private Map<trainId, Train> trains;
private Ticketdetails ticketdetails;
private PaymentDetails paymentDetails;
private TrainTicket tt;
public vector<Train> getTrain(TicketDetails ticketdetails);
public TrainTicket purchaseTicket(TicketDetails ticketDetails,
PaymentDetails paymentDetails);
public boolean cancelTicket(TrainTicket tt, PaymentDetails details);
public TrainTicket modifyTicket(TrainTicket existingTicket,
TicketDetails newTicketDetails, PaymentDetails paymentDetails);
}
我想知道主 Reservation 类应该如何访问其他类的方法和成员。
提前致谢。
【问题讨论】：