import java.util.Scanner;

public class PrintCalendar {

/** Main method */

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

// Prompt the user to enter year

System.out.print("Enter full year (e.g., 2012): ");

int year = input.nextInt();

// Prompt the user to enter month

System.out.print("Enter month as a number between 1 and 12: ");

int month = input.nextInt();

// Print calendar for the month of the year

printMonth(year, month);

}

/** Print the calendar for a month in a year */

public static void printMonth(int year, int month) {

// Print the headings of the calendar

printMonthTitle(year, month);

// Print the body of the calendar

printMonthBody(year, month);

}

/** Print the month title, e.g., March 2012 */

public static void printMonthTitle(int year, int month) {

System.out.println(" " + getMonthName(month)

+ " " + year);

System.out.println("-----------------------------");

System.out.println(" Sun Mon Tue Wed Thu Fri Sat");

}

/** Get the English name for the month */

public static String getMonthName(int month) {

String monthName = "";

switch (month) {

case 1: monthName = "January"; break;

case 2: monthName = "February"; break;

case 3: monthName = "March"; break;

case 4: monthName = "April"; break;

case 5: monthName = "May"; break;

case 6: monthName = "June"; break;

case 7: monthName = "July"; break;

case 8: monthName = "August"; break;

case 9: monthName = "September"; break;

case 10: monthName = "October"; break;

case 11: monthName = "November"; break;

case 12: monthName = "December";

}

return monthName;

}

/** Print month body */

public static void printMonthBody(int year, int month) {

// Get start day of the week for the first date in the month

int startDay = getStartDay(year, month);

// Get number of days in the month

int numberOfDaysInMonth = getNumberOfDaysInMonth(year, month);

// Pad space before the first day of the month

int i = 0;

for (i = 0; i < startDay; i++)

System.out.print(" ");

for (i = 1; i <= numberOfDaysInMonth; i++) {

System.out.printf("%4d", i);

if ((i + startDay) % 7 == 0)

System.out.println();

}

System.out.println();

}

/** Get the start day of month/1/year */

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

final int START_DAY_FOR_JAN_1_1800 = 3;

// Get total number of days from 1/1/1800 to month/1/year

int totalNumberOfDays = getTotalNumberOfDays(year, month);

// Return the start day for month/1/year

return (totalNumberOfDays + START_DAY_FOR_JAN_1_1800) % 7;

}

/** Get the total number of days since January 1, 1800 */

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

int total = 0;

// Get the total days from 1800 to 1/1/year

for (int i = 1800; i < year; i++)

if (isLeapYear(i))

total = total + 366;

else

total = total + 365;

// Add days from Jan to the month prior to the calendar month

for (int i = 1; i < month; i++)

total = total + getNumberOfDaysInMonth(year, i);

return total;

}

/** Get the number of days in a month */

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

if (month == 1 || month == 3 || month == 5 || month == 7 ||

month == 8 || month == 10 || month == 12)

return 31;

if (month == 4 || month == 6 || month == 9 || month == 11)

return 30;

if (month == 2) return isLeapYear(year) ? 29 : 28;

return 0; // If month is incorrect

}

/** Determine if it is a leap year */

public static boolean isLeapYear(int year) {

return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);

}

Modify a Java program meeting the following requirements . Using the program provided, PrintCalendar, you are to modify the program to validate the year entered is numeric, positive, and the correct length of four digits. You will also validate the month entered is from 1 to 12. If either is incorrect you need to create a Custom Exception class that states the problem, and allows the member to change either the year or month, using a Try...Catch block. Once you have validated the data you need to print out the calendar for the month entered.