date

package programming.set6.date;

/**
 * This class named date is a program that should return a date in a valid and
 * given format.
 *
 * @author Marielouise
 *
 */
public class Date {
	private int year;
	private int month;
	private int day;
	private static final String[] MONTHS = { "January", "February", "March",
			"April", "May", "June", "July", "August", "September", "October",
			"November", "December" };

	/**
	 * The method getDaysInMonth have two parameters.
	 *
	 * @param year
	 *            in which we are counting.
	 * @param month
	 *            that we are counting the days.
	 * @return the number of days of a given year.
	 */

	public static int getDaysInMonth(int year, int month) {

		switch (month) {

		case 1: // "January";
		case 3: // "March";
		case 5: // "May";
		case 7: // "July";
		case 8: // "August";
		case 10: // "October";
		case 12: // "December";
			return 31;

		case 4: // "April";
		case 6: // "June";
		case 9: // "September";
		case 11: // "November";
			return 30;

		case 2: // "February";
			if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) {
				return 29;
			} else {
				return 28;
			}
		default: // out of range
			return 0;
		}

	}

	/**
	 * This is the method validate with three parameters of type integer.
	 *
	 * @param year
	 *            of the date to validate.
	 * @param month
	 *            of the date to validate.
	 * @param day
	 *            of the date to validate.
	 * @return a valid date.
	 */
	public static boolean validate(int year, int month, int day) {
		// boolean validate == true;
		if (month < 1 || month > 12) {
			return false;
		} else if (day < 1 || day > getDaysInMonth(year, month)) {
			return false;
		} else {
			return true;
		}

	}

	/**
	 * This method return a date.
	 *
	 * @param year
	 *            of the date.
	 * @param month
	 *            of the date
	 * @param day
	 *            of the date.
	 */

	public Date(int year, int month, int day) {
		if (validate(year, month, day)) {
			this.year = year;
			this.month = month;
			this.day = day;
		} else {
			throw new IllegalArgumentException("This is not a valid date.");

		}
	}

	/**
	 * This method get the day.
	 *
	 * @return a given day.
	 */
	public int getDay() {
		return day;
	}

	/**
	 * This method get the month.
	 *
	 * @return a given month.
	 */
	public int getMonth() {
		return month;
	}

	/**
	 * This method get the year.
	 *
	 * @return a given year.
	 */
	public int getYear() {
		return year;
	}

	/**
	 * This method calculate the numbers of days for a given date of the year.
	 *
	 * @return the number of days till this date or between two days.
	 */
	public int dayOfYear() {
		int dayOfYear = 0;
		for (int i = 0; i < month; i++) {
			dayOfYear = dayOfYear + getDaysInMonth(year, i);
		}
		dayOfYear = dayOfYear + day;
		return dayOfYear;
	}

	/**
	 * This method calculate how many days the other date is off.
	 *
	 * @param other
	 *            is the other date we need to make the difference.
	 * @return the result in integer form.
	 */
	public int sameYearDiff(Date other) {
		if (year == other.getYear()) {
			return other.dayOfYear() - dayOfYear();
		} else {
			return 0;
		}

	}

	/**
	 * This is the method that return a date in a given format.
	 * @return the date in a given format.
	 */
	public String toString() {

		return MONTHS[month - 1] + "  " + day + " , " + year;
	}

	/**
	 * This is the method to test our program.
	 *
	 * @param args
	 *            we need to check the date.
	 */
	public static void main(String[] args) {
		Date date = new Date(2015, 5, 20);
		System.out.println(date);

	}

}