java 对日期函数的操作（Calendar的使用）

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package test6;/* * 演示 Calendar 的一般操作 */import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;public class Test {public Test() {}public static void main(String[] args) {// 字符串转换日期格式// DateFormat fmtDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 得到日期格式对象// Date date = fmtDateTime.parse(strDateMake);// 完整显示日期时间String str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(new Date());System.out.println(str);// 创建 Calendar 对象Calendar calendar = Calendar.getInstance();// 初始化 Calendar 对象，但并不必要，除非需要重置时间calendar.setTime(new Date());// setTime 类似上面一行// Date date = new Date();// calendar.setTime(date);// 显示年份int year = calendar.get(Calendar.YEAR);System.out.println("YEAR is = " + String.valueOf(year));// 显示月份 (从0开始, 实际显示要加一)int MONTH = calendar.get(Calendar.MONTH);System.out.println("MONTH is = " + (MONTH + 1));// 今年的第 N 天int DAY_OF_YEAR = calendar.get(Calendar.DAY_OF_YEAR);System.out.println("DAY_OF_YEAR is = " + DAY_OF_YEAR);// 本月第 N 天int DAY_OF_MONTH = calendar.get(Calendar.DAY_OF_MONTH);System.out.println("DAY_OF_MONTH = " + String.valueOf(DAY_OF_MONTH));// 3小时以后calendar.add(Calendar.HOUR_OF_DAY, 3);int HOUR_OF_DAY = calendar.get(Calendar.HOUR_OF_DAY);System.out.println("HOUR_OF_DAY + 3 = " + HOUR_OF_DAY);// 当前分钟数int MINUTE = calendar.get(Calendar.MINUTE);System.out.println("MINUTE = " + MINUTE);// 15 分钟以后calendar.add(Calendar.MINUTE, 15);MINUTE = calendar.get(Calendar.MINUTE);System.out.println("MINUTE + 15 = " + MINUTE);// 30分钟前calendar.add(Calendar.MINUTE, -30);MINUTE = calendar.get(Calendar.MINUTE);System.out.println("MINUTE - 30 = " + MINUTE);// 格式化显示str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());System.out.println(str);// 重置 Calendar 显示当前时间calendar.setTime(new Date());str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());System.out.println(str);// 创建一个 Calendar 用于比较时间Calendar calendarNew = Calendar.getInstance();// 设定为 5 小时以前，后者大，显示 -1calendarNew.add(Calendar.HOUR, -5);System.out.println("时间比较：" + calendarNew.compareTo(calendar));// 设定7小时以后，前者大，显示 1calendarNew.add(Calendar.HOUR, +7);System.out.println("时间比较：" + calendarNew.compareTo(calendar));// 退回 2 小时，时间相同，显示 0calendarNew.add(Calendar.HOUR, -2);System.out.println("时间比较：" + calendarNew.compareTo(calendar));}}
引用：http://blog.csdn.net/kpchen_0508/article/details/48367401
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