Java 输入一个字符串格式日期，获取对应的自然月开始结束时间，对应的自然年开始结束时间

public static Map getMonthStartTimeByDate(String dateTime) throws ParseException {

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");

Date date = simpleDateFormat.parse(dateTime);

long currentTime = date.getTime();

String timeZone = "GMT+8:00";

Calendar calendar = Calendar.getInstance();// 获取当前日期

calendar.setTimeZone(TimeZone.getTimeZone(timeZone));

calendar.setTimeInMillis(currentTime);

calendar.add(Calendar.YEAR, 0);

calendar.add(Calendar.MONTH, 0);

calendar.set(Calendar.DAY_OF_MONTH, 1);// 设置为 1 号,当前日期既为本月第一天

calendar.set(Calendar.HOUR_OF_DAY, 0);

calendar.set(Calendar.MINUTE, 0);

calendar.set(Calendar.SECOND, 0);

calendar.set(Calendar.MILLISECOND, 0);

long timeInMillis = calendar.getTimeInMillis();

Date resultStartDate = new Date(timeInMillis);

String resultStartTime = simpleDateFormat.format(resultStartDate);

Calendar calendar2 = Calendar.getInstance();// 获取当前日期

calendar2.setTimeZone(TimeZone.getTimeZone(timeZone));

calendar2.setTimeInMillis(currentTime);

calendar2.add(Calendar.YEAR, 0);

calendar2.add(Calendar.MONTH, 0);

calendar2.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));// 获取当前月最后一天

calendar2.set(Calendar.HOUR_OF_DAY, 23);

calendar2.set(Calendar.MINUTE, 59);

calendar2.set(Calendar.SECOND, 59);

calendar2.set(Calendar.MILLISECOND, 999);

long timeInMillis2 = calendar2.getTimeInMillis();

Date resultEndDate = new Date(timeInMillis2);

String resultEndTime = simpleDateFormat.format(resultEndDate);

Map map = new HashMap();

map.put("startDate", resultStartTime);

map.put("endDate", resultEndTime);

return map;

}

//输入一个时间,获取对应的自然年开始时间,结束时间

public static Map getYearStartTimeByDate(String dateTime) throws ParseException {

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");

Date date = simpleDateForma 《一线大厂 Java 面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 t.parse(dateTime);

GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();

gc.setTime(date);

Calendar cal = Calendar.getInstance();

cal.set(Calendar.YEAR, Integer.valueOf(gc.get(1)));

cal.set(Calendar.MONTH, Calendar.JANUARY);

cal.set(Calendar.DATE, 1);

Long dayStartTime = getDayStartTime(cal.getTime());

Date resultStartDate = new Date(dayStartTime);

String resultStartTime = simpleDateFormat.format(resultStartDate);

Calendar cal2 = Calendar.getInstance();

cal2.set(Calendar.YEAR, Integer.valueOf(gc.get(1)));

cal2.set(Calendar.MONTH, Calendar.DECEMBER);

cal2.set(Calendar.DATE, 31);

Long dayEndTime = getDayStartTime(cal2.getTime());

Date resultEndDate = new Date(dayEndTime);

String resultEndTime = simpleDateFormat.format(resultEndDate);

Map map = new HashMap();

map.put("startDate", resultStartTime);

map.put("endDate", resultEndTime);

return map;

}