exercise3_34.java

java程序设计导论（daniel liang著） 所有偶数课后习题答案

// Exercise3_34.java
import javax.swing.*;

public class Exercise3_34 {
    public static void main(String[] args) {
        // Prompt the user to enter input
        String yearString = JOptionPane.showInputDialog("Enter a year:");
        int year = Integer.parseInt(yearString);
        
        String firstDayString = JOptionPane.showInputDialog("Enter the first day of the year:");
        int firstDay = Integer.parseInt(firstDayString);
        
        int startDay = firstDay;
        int numberOfDaysInMonth = 0;
        
        // Display calendar for each month
        for (int month = 1; month <= 12; month++) {
            // Display Calendar title
            System.out.print("          ");
            switch (month) {
                case 1: System.out.println("January " + year);
                numberOfDaysInMonth = 31;
                break;
                case 2: System.out.println("Feburary " + year);
                if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
                    numberOfDaysInMonth = 29;
                else
                    numberOfDaysInMonth = 28;
                break;
                case 3: System.out.println("March " + year);
                numberOfDaysInMonth = 31;
                break;
                case 4: System.out.println("April " + year);
                numberOfDaysInMonth = 30;
                break;
                case 5: System.out.println("May " + year);
                numberOfDaysInMonth = 31;
                break;
                case 6: System.out.println("June " + year);
                numberOfDaysInMonth = 30;
                break;
                case 7: System.out.println("July " + year);
                numberOfDaysInMonth = 31;
                break;
                case 8: System.out.println("August " + year);
                numberOfDaysInMonth = 31;
                break;
                case 9: System.out.println("September " + year);
                numberOfDaysInMonth = 30;
                break;
                case 10: System.out.println("October " + year);
                numberOfDaysInMonth = 31;
                break;
                case 11: System.out.println("November " + year);
                numberOfDaysInMonth = 30;
                break;
                case 12: System.out.println("December " + year);
                numberOfDaysInMonth = 31;
                break;
            }
            
            System.out.println("-----------------------------");
            System.out.println(" Sun Mon Tue Wed Thu Fri Sat");
            
            // 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++) {
                if (i < 10)
                    System.out.print("   " + i);
                else
                    System.out.print("  " + i);
                
                if ((i + startDay) % 7 == 0)
                    System.out.println();
            }
            
            System.out.println();
            System.out.println();
            
            // Get the start day for the next month
            startDay = (startDay + numberOfDaysInMonth) % 7;
            
            
            
            
        }
        
        System.exit(0);
    }
    
}