java - 如何在约会类中创建列表以及如何编写测试用例？

Question

实现父类(super class)约会和子类一次性、每日和每月。
预约有描述(例如，“看牙医”)和日期。
编写一个方法 events On(intyear,intmonth,intday) 来检查约会是否发生在该日期。
例如，对于每月的约会，您必须检查该月的某一天是否匹配，然后用约会的混合填充 Appointment 对象的数组。
让用户输入一个日期并打印出该日期发生的所有约会。

public class Appointment {

    private String description;
    private Date date;

    public Appointment(String description, int day, int month, int year) 
        throws ParseException {
        this.description=description;
        SimpleDateFormat simpleDateFormat = new 
        SimpleDateFormat("dd/MM/yyyy");
        this.setDate(simpleDateFormat.parse(String.format("%d/%d/%d", day, 
        month, year)));

    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    @Override
    public String toString() {
        return String.format("Your Appointment is : %s. On(date): ", 
        this.getDescription(), this.getDate()
                .toString());
    }

    public boolean occursOn(int year, int month, int day) throws 
        ParseException {
        SimpleDateFormat simpleDateFormat = new 
        SimpleDateFormat("dd/MM/yyyy");
        Date date = simpleDateFormat.parse(String.format("%d/%d/%d", day, 
        month, year));

        return this.getDate().equals(date);
    }
}

Answer 1

将Appointment 基类与occurrsOn 方法一起抽象化。同时删除 date 变量，因为某些子类不需要它:

public abstract class Appointment {

    private String description;

    public Appointment(String description) 
        this.description=description;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public abstract boolean occursOn(int year, int month, int day) throws 
        ParseException;
}

现在我们可以开始创建子类，它将实现 occurrsOn 方法。对于 Onetime 子类，它将与原始 Appointment 类基本相同，因此我现在不会编写它。相反，让我们看一下每月，例如:

public class Monthly extends Appointment {

    private String description;
    private int onThisDay; //on this day of the month is the appointment

    public Appointment(String description, int onThisDay) {
        this.description=description;
        this.onThisDay = onThisDay;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    //override tostring as well
    @Override
    public String toString() {
        return "Your " + description + " appointment is on the " +
        onThisDay + ". day of the month";
    }

    //implement our abstract method, month and year params have no importance here
    public boolean occursOn(int year, int month, int day) throws 
        ParseException {
        return day == onThisDay; //just check if day matches
    }
}

关于如何填写约会列表，这里是:

List<Appointment> appointments = new ArrayList<>();
//2 appointments for example
appointments.addAll(new Onetime("Doctor",2019,07,21), new Monthly("Dentist",11));
appointments.forEach(app -> System.out.println(app.toString())); //print all