Question

In Java, implement a superclass Appointment and subclasses Onetime, Daily, and Monthly. An appointment has a description (for example, “see the dentist”) and a date. Write a method
occursOn(int year, int month, int day) that checks whether the appointment occurs on that date. For example, for a monthly appointment, you must check whether the day of the month matches.

In Main Class, fill an array of Appointment objects with a mixture of appointments i.e Onetime, Daily, and Monthly (at least 1 from each). Then prompt the user to enter a date and print out all appointments that occur on that date.

Answer 1

Hi,

Please find the answer below:
-------------------------------

Java Program:

package appointment;

/******************************************************************************
*Appointment.java
******************************************************************************/
public class Appointment {
   protected String description;
   protected int day;
   protected int month;
   protected int year;

   //Appointment Constructor
   public Appointment(String desc, int d, int m, int y)
   {
       this.description = desc;
       this.day = d;
       this.month = m;
       this.year = y;
   }

   //getters and setters
   public String getDescription() {
       return description;
   }

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

   public int getDay() {
       return day;
   }

   public void setDay(int day) {
       this.day = day;
   }

   public int getMonth() {
       return month;
   }

   public void setMonth(int month) {
       this.month = month;
   }

   public int getYear() {
       return year;
   }

   public void setYear(int year) {
       this.year = year;
   }

    // this method would be overridden in the subclasses
   public boolean occursOn(int d, int m, int y)
   {
       if(getDay() == d && getMonth() == m && getYear() == y)
           return true;
       else
           return false;
   }

   //toString()
   public String toString()
   {
       return description + " on "+ day + "/" + month + "/" +year ;
   }

}

----------------

package appointment;

/******************************************************************************
* OneTime.java
* @author
*
*****************************************************************************/
public class OneTime extends Appointment {

   public OneTime(String desc, int d, int m, int y) {
       super(desc, d, m, y);
   }

   public String toString()
   {
       return "OneTime Appt -" + super.toString();
   }

}

-----------------

package appointment;

/******************************************************************************
* Daily.java
* @author
*
*****************************************************************************/
public class Daily extends Appointment {

   public Daily(String desc, int d, int m, int y) {
       super(desc, d, m, y);
   }

   //daily events except future events
   public boolean occursOn(int d, int m, int y)
   {
       if(getDay() < d || getYear() < y || getMonth() < m)
           return true;
       else
           return false;
   }

   public String toString()
   {
       return "Daily Appt -"+ description +" from " + getDay() + "/" + getMonth() + "/" + getYear();

   }

}

----------------

package appointment;

/******************************************************************************
* Monthly.java
* @author
*
*****************************************************************************/
public class Monthly extends Appointment {

   public Monthly(String desc, int d, int m, int y) {
       super(desc, d, m, y);
   }

   public boolean occursOn(int d, int m, int y)
   {
       //future events are not returned
       if(getDay() == d && (getYear() < y || getMonth() < m))
           return true;
       else
           return false;
   }

   public String toString()
   {
       return "Monthly Appt - "+ description + " on the day " + day + " of the month from " + getMonth() + "/" + getYear();
   }

}

-------------

package appointment;

import java.util.Scanner;

public class Main {
   public static void main(String[] args) {
       int day,month,year;
       Appointment[] appointments= new Appointment[6];
       appointments[0]= new OneTime("Get Together",1,1,2019);
       appointments[1]=new Monthly("Pay Electric bill",1,2,2019);
       appointments[2]= new Daily("Get Milk Packets",1,1,2017);
       appointments[3]= new OneTime("Meeting School Friend",1,1,2020);
       appointments[4]=new Monthly("Pay House Tax",1,3,2019);
       appointments[5]= new Daily("Gym Visit",2,1,2020);
       Scanner scanner = new Scanner(System.in);
       System.out.println("Enter date to show appointments:");
       System.out.println("Enter day: ");
       day = scanner.nextInt();
       System.out.println("Enter month: ");
       month = scanner.nextInt();
       System.out.println("Enter year: ");
       year = scanner.nextInt();
      
       System.out.println("Appointments are : ");
       for(Appointment a : appointments) {
           if(a.occursOn(day, month, year))
               System.out.println(a.toString());
       }
   }
}

-----------------

Program Output:

Enter date to show appointments:
Enter day:
1
Enter month:
1
Enter year:
2021
Appointments are :
Monthly Appt - Pay Electric bill on the day 1 of the month from 2/2019
Daily Appt -Get Milk Packets from 1/1/2017
Monthly Appt - Pay House Tax on the day 1 of the month from 3/2019
Daily Appt -Gym Visit from 2/1/2020

Screenshot:

-------------------------------
Hope this helps.
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Thanks.