OOP Train & reservation system

import java.util.ArrayList;

import java.util.Hashtable;

class station{

    String stationID;

}

class Train{

    String trainID;

    int numOfCars;

    int maxCapacity;

    int NumOfPassenger;

    float price;

     

    Hashtable<String,station> schedule;//time, station

}

public class trainReservation {

    //id, train

    Hashtable <String, Train> trains = new Hashtable <String, Train>();

     

    float reserveSit(station sta, String time, String trainID ){

        //no such train

        if(!trains.containsKey(trainID)) return 0;

        Train train = trains.get(trainID);

        //full

        if(train.NumOfPassenger==train.maxCapacity)return 0;

        //in the time, train in different station

        if(!sta.stationID.equals(train.schedule.get(time))) return 0;

        //order now

        train.NumOfPassenger++;

        trains.put(trainID, train);

        return train.price;

    }

    //vice versa for cancel

}