Core Java (六) 打印指定月份的日历

更改的core java的一个程序，利用了GregorianCalendar这个类。

输入年份以及月份，打印出指定月份的日历。

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1package com.xujin;

2

3import java.text.DateFormatSymbols;

4import java.util.Calendar;

5import java.util.GregorianCalendar;

6import java.util.Locale;

7import java.util.Scanner;

8

9public class Test {

10  static Scanner cin = new Scanner(System.in);

11  public static void main(String[] args){

12      Locale.setDefault(Locale.US);//设置为美国地区

13      System.out.print("Please input the year and month(like 1999 9):");        

14      int year = cin.nextInt();

15      int month = cin.nextInt();      

16      GregorianCalendar day = new GregorianCalendar();//从公元 4 年 3 月 1 日之后是准确的

17      

18      //将day设置为该月的第一天

19      day.set(Calendar.YEAR, year);

20      day.set(Calendar.MONTH, month - 1);     

21      day.set(Calendar.DAY_OF_MONTH, 1);

22      

23      int weekday = day.get(Calendar.DAY_OF_WEEK);        

24      int firstDayOfWeek = day.getFirstDayOfWeek();

25      

26      int indent = 0;

27      while(weekday != firstDayOfWeek){

28          indent++;

29          day.add(Calendar.DAY_OF_MONTH, -1);

30          weekday = day.get(Calendar.DAY_OF_WEEK);

31      }

32      

33      String[] weekdayNames = new DateFormatSymbols().getShortWeekdays(); 

34      do{

35          System.out.printf("%4s", weekdayNames[weekday]);

36          day.add(Calendar.DAY_OF_MONTH, 1);

37          weekday = day.get(Calendar.DAY_OF_WEEK);

38      }while(weekday != firstDayOfWeek);

39      System.out.println();

40      

41      for(int i = 0; i < indent; i++)

42          System.out.print("    ");

43      day.set(Calendar.DAY_OF_MONTH, 1);

44      

45      do{

46          int d = day.get(Calendar.DAY_OF_MONTH);

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

48          

49          day.add(Calendar.DAY_OF_MONTH, 1);

50          weekday = day.get(Calendar.DAY_OF_WEEK);

51          

52          if(weekday == firstDayOfWeek) System.out.println();

53      }while(month - 1 == day.get(Calendar.MONTH));

54      

55      if(weekday != firstDayOfWeek) System.out.println();

56  }

57  

58}

59

结果：