日期相关操作

代码在java8测试过，默认返回的日期都是零点时间戳

 

1. 获取某一周的第一天

public long getWeekMonday(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);
    // 设置一周的第一天是星期一
    cal.setFirstDayOfWeek(Calendar.MONDAY);
    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

2. 获取某一周的最后一天

public long getWeekSunday(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);
    // 设置一周的第一天是星期一
    cal.setFirstDayOfWeek(Calendar.MONDAY);
    cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

 

3. 获取某个月的第一天

public long getFirstDayOfMonth(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);
    cal.set(Calendar.DAY_OF_MONTH, 1);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

 

4. 获取某个月的最后一天

public long getLastDayOfMonth(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);
    cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

5. 获取某个季度第一天

public long getFirstDayOfQuarter(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);

    int month = cal.get(Calendar.MONTH);
    int firstMonth = month / 3 * 3;

    cal.set(Calendar.MONTH, firstMonth);
    cal.set(Calendar.DAY_OF_MONTH, 1);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

6. 获取每个季度最后一天

public long getLastDayOfQuarter(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);

    int month = cal.get(Calendar.MONTH);
    int lastMonth = month / 3 * 3 + 2;

    cal.set(Calendar.MONTH, lastMonth);
    cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

7. 获取某一年第一天

public long getFirstDayOfYear(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);

    cal.set(Calendar.MONTH, Calendar.JANUARY);
    cal.set(Calendar.DAY_OF_MONTH, 1);
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}

 

8. 获取某一年最后一天

public long getLastDayOfYear(long millis) {
    Calendar cal = Calendar.getInstance();

    cal.setTimeInMillis(millis);

    cal.set(Calendar.MONTH, Calendar.DECEMBER);
    cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    return cal.getTimeInMillis();
}