MyDate.java

MyDate.java

// Fixed IncrementDate method
// 10/08/18

import java.util.Calendar;

public class MyDate extends Object {
	private int month;
	private int day;
	private int year;

	// Getters and Setters
	
	public int getMonth() {
		return month;
	}

	public int getDay() {
		return day;
	}

	public int getYear() {
		return year;
	}	
	
	public void setDate(int month, int day, int year) {
		setYear(year);
		setMonth(month);
		setDay(day);
	}

	private void setYear(int y) {
		if (y >= 1)
			year = y;
		else
			System.err.println("ERROR: Bad Year Specified: " + y);
	}

	private void setMonth(int m) {
		if (m >= 1 && m <= 12)
			month = m;
		else
			System.err.println("ERROR: Bad Month Specified: " + m);
	}

	private void setDay(int d) {
		switch (month) {
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:
			if (d >= 1 && d <= 31)
				day = d;
			else
				System.err.println("ERROR: Bad Day Specified: " + d
						+ " for month: " + month);
			break;
		case 4:
		case 6:
		case 9:
		case 11:
			if (d >= 1 && d <= 30)
				day = d;
			else
				System.err.println("ERROR: Bad Day Specified: " + d
						+ " for month: " + month);
			break;
		case 2:
			if (this.isLeapYear())
				if (d >= 1 && d <= 29)
					day = d;
				else
					System.err.println("ERROR: Bad Day Specified: " + d
							+ " for leapyear February");
			else if (d >= 1 && d <= 28)
				day = d;
			else
				System.err.println("ERROR: Bad Day Specified: " + d
						+ " for leapyear February");
			break;
		default:
			System.err.println("ERROR: VERY BAD MONTH: " + month);
		    break;
		}
	}

	// Constructors
	
	public MyDate(int month, int day, int year) {
		this.setDate(month, day, year);
	}

	public MyDate() {
		Calendar x = Calendar.getInstance();
		month = x.get(Calendar.MONTH) + 1;
		day = x.get(Calendar.DATE);
		year = x.get(Calendar.YEAR);
	}

	
	public MyDate(int month, int year) {
		this.setDate(month, 1, year);
	}
	
	
	public MyDate(int year) {
		this.setDate(1, 1, year);
	}	
	
	// Utility Methods

	private static int getDaysInMonth(int month, boolean isLeap) {
		int noOfDays = 0;

		switch (month) {
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:
			noOfDays = 31;
			break;
		case 4:
		case 6:
		case 9:
		case 11:
			noOfDays = 30;
			break;
		case 2:
			if (isLeap)
				noOfDays = 29;
			else
				noOfDays = 28;
			break;
		}
		return noOfDays;
	}
	
	public int getDaysInMonth() {
		return getDaysInMonth(this.month, this.isLeapYear());
	}

	public int numberOfDaysLeft() {
		if (isLeapYear())
			return 366 - numberOfDaysPassed();
		else
			return 365 - numberOfDaysPassed();
	}

	public int numberOfDaysPassed() {
		int sumDays = 0;
		for (int i = 1; i < month; i++)
			sumDays += getDaysInMonth(i, isLeapYear());
		sumDays += day;
		return sumDays;
	}

	public void incrementDate(int nDays) {
		for (int i = 0; i < nDays; i++) {
			this.day++;
			if (this.day > getDaysInMonth(this.month, this.isLeapYear())) {
				this.day = 1;
				this.month++;
				if (this.month > 12) {
					this.month = 1;
					this.year++;
				}
			}
		}
	}

	public boolean isLeapYear() {
		return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
	}
	
	public String toString() {
		return String.format("%02d/%02d/%02d", month, day, year);
	}

}