Java Calendar使用总结

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Java Calendar 类时间操作，这也许是创建和管理日历最简单的一个方案，示范代码很简单。
演示了获取时间，日期时间的累加和累减，以及比较。

原文地址：blog.csdn.NET/joyous/article/details/9630893

注意事项：
Calendar 的 month 从 0 开始，也就是全年 12 个月由 0 ~ 11 进行表示。
而 Calendar.DAY_OF_WEEK 定义和值如下：
Calendar.SUNDAY = 1
Calendar.MONDAY = 2
Calendar.TUESDAY = 3
Calendar.WEDNESDAY = 4
Calendar.THURSDAY = 5
Calendar.FRIDAY = 6
Calendar.SATURDAY = 7

SimpleDateFormat 的格式定义
LetterDate or Time ComponentPresentationExamplesGEra designatorTextADyYearYear1996; 96YWeek yearYear2009; 09MMonth in year (context sensitive)MonthJuly; Jul; 07LMonth in year (standalone form)MonthJuly; Jul; 07wWeek in yearNumber27WWeek in monthNumber2DDay in yearNumber189dDay in monthNumber10FDay of week in monthNumber2EDay name in weekTextTuesday; TueuDay number of week (1 = Monday, ..., 7 = Sunday)Number1aAm/pm markerTextPMHHour in day (0-23)Number0kHour in day (1-24)Number24KHour in am/pm (0-11)Number0hHour in am/pm (1-12)Number12mMinute in hourNumber30sSecond in minuteNumber55SMillisecondNumber978zTime zoneGeneral time zonePacific Standard Time; PST; GMT-08:00ZTime zoneRFC 822 time zone-0800XTime zoneISO 8601 time zone-08; -0800; -08:00

Java Calendar 演示代码如下：
[java] view plain copy
1. package demo;
3. import java.util.Date;
4. import java.text.SimpleDateFormat;
5. import java.text.DateFormat;
6. import java.text.ParseException;
7. import java.util.Calendar;
9. public class Test
10. {
11. public Test()
12. {
13. }
15. public static void main(String[] args)
16. {
17. // 字符串转换日期格式
18. // DateFormat fmtDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
19. // 接收传入参数
20. // String strDate = args[1];
21. // 得到日期格式对象
22. // Date date = fmtDateTime.parse(strDate);
24. // 完整显示今天日期时间
25. String str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(new Date());
26. System.out.println(str);
28. // 创建 Calendar 对象
29. Calendar calendar = Calendar.getInstance();
31. try
32. {
33. // 对 calendar 设置时间的方法
34. // 设置传入的时间格式
35. SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-M-d H:m:s");
36. // 指定一个日期
37. Date date = dateFormat.parse("2013-6-1 13:24:16");
38. // 对 calendar 设置为 date 所定的日期
39. calendar.setTime(date);
41. // 按特定格式显示刚设置的时间
42. str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());
43. System.out.println(str);
44. }
45. catch (ParseException e)
46. {
47. e.printStackTrace();
48. }
50. // 或者另一種設置 calendar 方式
51. // 分別爲 year, month, date, hourOfDay, minute, second
52. calendar = Calendar.getInstance();
53. calendar.set(2013, 1, 2, 17, 35, 44);
54. str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());
55. System.out.println(str);
57. // Calendar 取得当前时间的方法
58. // 初始化 (重置) Calendar 对象
59. calendar = Calendar.getInstance();
60. // 或者用 Date 来初始化 Calendar 对象
61. calendar.setTime(new Date());
63. // setTime 类似上面一行
64. // Date date = new Date();
65. // calendar.setTime(date);
67. str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());
68. System.out.println(str);
70. // 显示年份
71. int year = calendar.get(Calendar.YEAR);
72. System.out.println("year is = " + String.valueOf(year));
74. // 显示月份 (从0开始, 实际显示要加一)
75. int month = calendar.get(Calendar.MONTH);
76. System.out.println("nth is = " + (month + 1));
78. // 本周几
79. int week = calendar.get(Calendar.DAY_OF_WEEK);
80. System.out.println("week is = " + week);
82. // 今年的第 N 天
83. int DAY_OF_YEAR = calendar.get(Calendar.DAY_OF_YEAR);
84. System.out.println("DAY_OF_YEAR is = " + DAY_OF_YEAR);
86. // 本月第 N 天
87. int DAY_OF_MONTH = calendar.get(Calendar.DAY_OF_MONTH);
88. System.out.println("DAY_OF_MONTH = " + String.valueOf(DAY_OF_MONTH));
90. // 3小时以后
91. calendar.add(Calendar.HOUR_OF_DAY, 3);
92. int HOUR_OF_DAY = calendar.get(Calendar.HOUR_OF_DAY);
93. System.out.println("HOUR_OF_DAY + 3 = " + HOUR_OF_DAY);
95. // 当前分钟数
96. int MINUTE = calendar.get(Calendar.MINUTE);
97. System.out.println("MINUTE = " + MINUTE);
99. // 15 分钟以后
100. calendar.add(Calendar.MINUTE, 15);
101. MINUTE = calendar.get(Calendar.MINUTE);
102. System.out.println("MINUTE + 15 = " + MINUTE);
104. // 30分钟前
105. calendar.add(Calendar.MINUTE, -30);
106. MINUTE = calendar.get(Calendar.MINUTE);
107. System.out.println("MINUTE - 30 = " + MINUTE);
109. // 格式化显示
110. str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());
111. System.out.println(str);
113. // 重置 Calendar 显示当前时间
114. calendar.setTime(new Date());
115. str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());
116. System.out.println(str);
118. // 创建一个 Calendar 用于比较时间
119. Calendar calendarNew = Calendar.getInstance();
121. // 设定为 5 小时以前，后者大，显示 -1
122. calendarNew.add(Calendar.HOUR, -5);
123. System.out.println("时间比较：" + calendarNew.compareTo(calendar));
125. // 设定7小时以后，前者大，显示 1
126. calendarNew.add(Calendar.HOUR, +7);
127. System.out.println("时间比较：" + calendarNew.compareTo(calendar));
129. // 退回 2 小时，时间相同，显示 0
130. calendarNew.add(Calendar.HOUR, -2);
131. System.out.println("时间比较：" + calendarNew.compareTo(calendar));
132. }
133. }
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
/*初始化*/
Calendar cal = Calendar.getInstance();
int year = cal.get(Calendar.YEAR);//年
int month = cal.get(Calendar.MONTH)+1;//月
int day = cal.get(Calendar.DATE);//日
int hour = cal.get(Calendar.HOUR_OF_DAY);//时
int minute = cal.get(Calendar.MINUTE);//分
int second = cal.get(Calendar.SECOND);//秒
int weekday = cal.get(Calendar.DAY_OF_WEEK);//星期周日-周六对应1-7
int last = cal.getActualMaximum(cal.DAY_OF_MONTH); // 获取本月最大天数
int DAY_OF_YEAR = cal.get(Calendar.DAY_OF_YEAR);//今年的第几天
int DAY_OF_MONTH = cal.get(Calendar.DAY_OF_MONTH);//本月的第几天
System.out.println("现在是: "+year+" 年 "+month+" 月 "+day+
" 日 "+hour+" 时 "+minute+" 分 "+second+" 秒 "+"\nweekday: "+weekday
+" 本月天数 :"+last+" 今年的第几天:"+DAY_OF_YEAR+" 本月第几天:"+DAY_OF_MONTH);
cal.set(2013, 5, 4, 13, 44, 51);//年月日时分秒（月份0代表1月），毫秒不会自动清零
System.out.println(sdf.format(cal.getTime()));
cal.set(Calendar.MILLISECOND, 0);//毫秒清零
System.out.println(sdf.format(cal.getTime()));
cal.set(Calendar.YEAR, 2014);//年
cal.set(Calendar.MONTH, 7);//月（月份0代表1月）
cal.set(Calendar.DATE, 11);//日
cal.set(Calendar.HOUR_OF_DAY, 15);//时
cal.set(Calendar.MINUTE, 33);//分
cal.set(Calendar.SECOND, 32);//秒
System.out.println(sdf.format(cal.getTime()));
cal.setTime(new Date());
System.out.println(sdf.format(cal.getTime()));
cal.add(Calendar.YEAR, 1);//年
cal.add(Calendar.MONTH, 1);//月
cal.add(Calendar.DATE, 1);//日
cal.add(Calendar.HOUR_OF_DAY, -1);//时
cal.add(Calendar.MINUTE, 1);//分
cal.add(Calendar.SECOND, 1);//秒
System.out.println(sdf.format(cal.getTime()));
Calendar calendarNew = Calendar.getInstance();
calendarNew.add(Calendar.HOUR, -2);
System.out.println("时间比较：" + calendarNew.compareTo(cal));

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