Calendar类测试

时间:2024-04-14 17:54:41
public static void main(String[] args) throws ParseException
{
// 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 -1
calendarNew.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 1
calendarNew.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 0
calendarNew.add(Calendar.HOUR, -2);
System.out.println("时间比较:" + calendarNew.compareTo(calendar)); }
/**
* 根据time获得该time的月初
*
* @param time
* @return
*/
public static long getMonthStartByTime(long time)
{
Calendar calendar = new GregorianCalendar();
calendar.setTimeInMillis(time);
calendar.add(Calendar.MONTH, 0);
calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.clear(Calendar.MINUTE);
calendar.clear(Calendar.SECOND);
calendar.clear(Calendar.MILLISECOND); return calendar.getTimeInMillis();
} /**
* 根据time获得该time的月末
*
* @param time
* @return
*/
public static long getMonthEndByTime(long time)
{
Calendar calendar = new GregorianCalendar();
calendar.setTimeInMillis(time);
calendar.add(Calendar.MONTH, 0);
calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
     calendar.set(Calendar.HOUR_OF_DAY, 23);
     calendar.set(Calendar.MINUTE, 59);
     calendar.set(Calendar.SECOND, 59);
     calendar.set(Calendar.MILLISECOND, 999);
    return calendar.getTimeInMillis(); 
}

 
public static void main(String[] args) throws ParseException
{
// 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 (从开始, 实际显示要加一)
int MONTH = calendar.get(Calendar.MONTH);
System.out.println("MONTH is = " + (MONTH + )); // 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, );
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, );
MINUTE = calendar.get(Calendar.MINUTE);
System.out.println("MINUTE + 15 = " + MINUTE); // 30分钟前
calendar.add(Calendar.MINUTE, -);
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 -1
calendarNew.add(Calendar.HOUR, -);
System.out.println("时间比较:" + calendarNew.compareTo(calendar)); // 设定小时以后,前者大,显示 1
calendarNew.add(Calendar.HOUR, +);
System.out.println("时间比较:" + calendarNew.compareTo(calendar)); // 退回 2 小时,时间相同,显示 0
calendarNew.add(Calendar.HOUR, -);
System.out.println("时间比较:" + calendarNew.compareTo(calendar)); }