Introduction

  • In this blog, I am going to explain about the monthly calendar program in Java

Software Requirements

  • Java, Notepad.
Program
  1. import java.util.*;
  2. import java.text.*;
  4. public class MonthCalender {
  6. public final static String[] monthcalender = {
  7. "January",
  8. "February",
  9. "March",
  10. "April",
  11. "May",
  12. "June",
  13. "July",
  14. "August",
  15. "September",
  16. "October",
  17. "November",
  18. "December"
  19. };
  21. public final static int daysinmonths[] = {
  22. 31,
  23. 28,
  24. 31,
  25. 30,
  26. 31,
  27. 30,
  28. 31,
  29. 31,
  30. 30,
  31. 31,
  32. 30,
  33. 31
  34. };
  36. private void displayMonth(int month, int year) {
  38. // The number of days to leave blank at
  39. // the start of this month.
  41. int blankdays = 0;
  42. System.out.println(" " + monthcalender[month] + " " + year);
  44. if (month < 0 || month > 11) {
  45. throw new IllegalArgumentException(
  46. "Month " + month + " is not valid and must lie in between 0 and 11");
  47. }
  49. GregorianCalendar cldr = new GregorianCalendar(year, month, 1);
  50. System.out.println("Sunday Monday Tuesday Wednesday Thursday Friday Saturday");
  52. // Compute how much to leave before before the first day of the month.
  53. // getDay() returns 0 for Sunday.
  55. blankdays = cldr.get(Calendar.DAY_OF_WEEK) - 1;
  56. int daysInMonth = daysinmonths[month];
  58. if (cldr.isLeapYear(cldr.get(Calendar.YEAR)) && month == 1) {
  60. ++daysInMonth;
  61. }
  63. // Blank out the labels before 1st day of the month
  64. for (int i = 0; i < blankdays; i++) {
  65. System.out.print(" ");
  66. }
  68. for (int i = 1; i <= daysInMonth; i++) {
  70. // This "if" statement is simpler than messing with NumberFormat
  71. if (i <= 9) {
  72. System.out.print(" ");
  73. }
  74. System.out.print(i);
  76. if ((blankdays + i) % 7 == 0) { // Wrap if EOL
  77. System.out.println();
  78. } else {
  79. System.out.print(" ");
  80. }
  81. }
  82. }
  84. /**
  85. * Sole entry point to the class and application.
  86. * @param args Array of String arguments.
  87. */
  88. public static void main(String[] args) {
  90. int mon, yr;
  91. MonthCalender moncldr = new MonthCalender();
  93. if (args.length == 2) {
  94. moncldr.displayMonth(Integer.parseInt(args[0]) - 1, Integer.parseInt(args[1]));
  95. } else {
  96. Calendar todaycldr = Calendar.getInstance();
  97. moncldr.displayMonth(todaycldr.get(Calendar.MONTH), todaycldr.get(Calendar.YEAR));
  98. }
  99. }
  100. }
Output
one