Java8 added a class YearMonth to date, a card expiration date can be used and so on.
1.YearMonth
The default format is: 2007-12
Section 1.1 source code
* * @implSpec * This class is immutable and thread-safe. * * @since 1.8 */ public final class YearMonth implements Temporal, TemporalAdjuster, Comparable<YearMonth>, Serializable { /** * Serialization version. */ private static final long serialVersionUID = 4183400860270640070L; /** * Parser. */ private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder() .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD) .appendLiteral('-') .appendValue(MONTH_OF_YEAR, 2) .toFormatter(); /** * The year. */ private final int year; /** * The month-of-year, not null. */ private final int month;
As can be seen by the source code using the modified final YearMonth, YearMonth class is thread safe, while achieving Temporal, TemporalAdjuster, Comparable <YearMonth>, Serializable interface attributes have read, set and subtraction functions.
1.2 to create and use a basic
YearMonth yearMonth = YearMonth.now(); YearMonth yearMonth2 = YearMonth.of(2020, 4); System.out.println(yearMonth); System.out.println(yearMonth2); YearMonth yearMonth3 = YearMonth.parse("2020-05"); System.out.println(yearMonth3); YearMonth yearMonth4 = yearMonth3.plusMonths(1); System.out.println(yearMonth4);
Output:
2020-03 2020-04 2020-05 2020-06
2. Applications
2.1 Conversion
The Date turn YearMonth, YearMonth like transfer Date
/** * Date转YearMonth * @param date * @return */ public static YearMonth toYearMonth(Date date){ LocalDate localDate = toLocalDate(date); return YearMonth.of(localDate.getYear(), localDate.getMonthValue()); } /** * LocalDateTime转YearMonth * @param localDateTime * @return */ public static YearMonth toYearMonth(LocalDateTime localDateTime){ LocalDate localDate = toLocalDate(localDateTime); return YearMonth.of(localDate.getYear(), localDate.getMonthValue()); } /** * LocalDate转YearMonth * @param localDate * @return */ public static YearMonth toYearMonth(LocalDate localDate){ Objects.requireNonNull(localDate, "localDate"); return YearMonth.of(localDate.getYear(), localDate.getMonthValue()); } /** * Instant转YearMonth * @param instant * @return */ public staticToYearMonth YearMonth (the Instant Instant) { the LocalDate localDate = toLocalDate (Instant); return YearMonth.of (localDate.getYear (), localDate.getMonthValue ()); } / ** * ZonedDateTime turn YearMonth * @param ZonedDateTime * @return * / public static YearMonth toYearMonth (ZonedDateTime ZonedDateTime) { the localDate localDate = toLocalDate (ZonedDateTime); return YearMonth.of (localDate.getYear (), localDate.getMonthValue ()); } / ** * YearMonth转Date * Note dayOfMonth range: between 1 to 31, The maximum value determination month special circumstances, such as the leap year February 29, non-leap years 28 * If you want to convert to the last day of the month, the following methods may be used: toDateEndOfMonth (YearMonth) * @param yearMonth * @param the dayOfMonth * @return * / public static a Date toDate (YearMonth yearMonth, int the dayOfMonth) { Objects.requireNonNull (yearMonth, " yearMonth " ); return toDate (yearMonth.atDay (the dayOfMonth)); } / ** * yearMonth turn Date, converting the first day of the month * @param yearMonth * @return * / public staticToDateStartOfMonth DATE (YearMonth yearMonth) { return toDate (yearMonth,. 1 ); } / ** * YearMonth turn Date, is converted to the last day of the month * @param yearMonth * @return * / public static DATE toDateEndOfMonth (YearMonth yearMonth) { Objects.requireNonNull (yearMonth, "yearMonth" ); return toDate (yearMonth.atEndOfMonth ()); } / ** * yearMonth turn the LocalDate * Note dayOfMonth range: between 1 to 31, a maximum value is determined in accordance with special circumstances month, such as February 29 leap year , a non-leap year 28 * If you want to convert to the last day of the month, you can use the following method: toLocalDateEndOfMonth (YearMonth) * @param yearMonth * @paramthe dayOfMonth * @return * / public static the LocalDate toLocalDate (YearMonth yearMonth, int the dayOfMonth) { Objects.requireNonNull (yearMonth, "yearMonth" ); return yearMonth.atDay (the dayOfMonth); } / ** * YearMonth turn LocalDate, conversion of the month one day * @param yearMonth * @return * / public static the LocalDate toLocalDateStartOfMonth (yearMonth yearMonth) { return toLocalDate (yearMonth,. 1 ); } / ** * yearMonth turn LocalDate, is converted to the last day of the month * @param yearMonth * @return */ public static LocalDate toLocalDateEndOfMonth(YearMonth yearMonth) { Objects.requireNonNull(yearMonth, "yearMonth"); return yearMonth.atEndOfMonth(); }
Test code:
@Test public void yearMonthConverterTest () { System.out.println ( "=================== yearMonthConverterTest =============== ====== " ); a Date DATE = new new a Date (); System.out.println (DATE); yearMonth yearMonth = DateTimeConverterUtil.toYearMonth (DATE); System.out.println (yearMonth); a Date date1 = DateTimeConverterUtil. toDate (yearMonth, 15 ); // convert first of the month a Date DATE2 = DateTimeConverterUtil.toDateStartOfMonth (yearMonth); // convert the last day of the month Date date3 =DateTimeConverterUtil.toDateEndOfMonth (yearMonth); System.out.println (date1); System.out.println (DATE2); System.out.println (date3); the LocalDate LocalDate1 = DateTimeConverterUtil.toLocalDate (yearMonth, 15 ); // convert The first day of the month the LocalDate LocalDate2 = DateTimeConverterUtil.toLocalDateStartOfMonth (yearMonth); // convert the last day of the month the LocalDate LocalDate3 = DateTimeConverterUtil.toLocalDateEndOfMonth (yearMonth); System.out.println (LocalDate1); System.out.println (LocalDate2); the System .out.println (LocalDate3); }
Output:
===================yearMonthConverterTest===================== Fri Mar 20 23:41:41 CST 2020 2020-03 Sun Mar 15 00:00:00 CST 2020 Sun Mar 01 00:00:00 CST 2020 Tue Mar 31 00:00:00 CST 2020 2020-03-15 2020-03-01 2020-03-31
2.2 computing
Get a list of dates in the middle of the start date, get a list of dates for a given month, whether or not expired, etc.
/** * 获取指定区间的时间列表，包含起始 * @param startInclusive * @param endInclusive * @return */ public static List<LocalDateTime> getLocalDateTimeList(LocalDateTime startInclusive, LocalDateTime endInclusive){ Objects.requireNonNull(startInclusive, "startInclusive"); Objects.requireNonNull(endInclusive, "endInclusive"); if(startInclusive.isAfter(endInclusive)){ throw new DateTimeException("startInclusive must before or equal endInclusive!"); } List<LocalDateTime> localDateTimeList = new ArrayList<LocalDateTime>(); long days = betweenTotalDays(startInclusive, endInclusive)+1; for(long i=0; i<days; i++){ localDateTimeList.add(startInclusive.plusDays(i)); } return localDateTimeList; } /** * 获取指定区间的时间列表，包含起始 * @param startInclusive * @param endInclusive * @return */ public static List<LocalDate> getLocalDateList(LocalDate startInclusive, LocalDate endInclusive){ return getLocalDateTimeList(DateTimeConverterUtil.toLocalDateTime(startInclusive), DateTimeConverterUtil.toLocalDateTime(endInclusive)).stream() .map(localDateTime -> localDateTime.toLocalDate()).collect(Collectors.toList()); } /** * 获取指定区间的时间列表，包含起始 * @param startInclusive * @param endInclusive * @return */ public static List<Date> getDateList(Date startInclusive, Date endInclusive){ return getLocalDateTimeList(DateTimeConverterUtil.toLocalDateTime(startInclusive), DateTimeConverterUtil.toLocalDateTime(endInclusive)).stream() .map(localDateTime -> DateTimeConverterUtil.toDate(localDateTime)).collect(Collectors.toList()); } /** * 获取指定年月的所有日期列表 * @param YearMonth * @return */ public static List<LocalDate> getLocalDateList(YearMonth yearMonth){ Objects.requireNonNull(yearMonth, "yearMonth"); List<LocalDate> localDateList = new ArrayList<LocalDate>(); long days = yearMonth.lengthOfMonth(); LocalDate localDate = DateTimeConverterUtil.toLocalDateStartOfMonth(yearMonth); for(long i=0; i<days; i++){ localDateList.add(plusDays(localDate, i)); } return localDateList; } /** * 获取指定年月的所有日期列表 * @param yearMonthStr yyyy-MM * @return */ public static List<LocalDate> getLocalDateList(String yearMonthStr){ Objects.requireNonNull(yearMonthStr, "yearMonthStr" ); YearMonth yearMonth = YearMonth.parse (yearMonthStr); return getLocalDateList (yearMonth); } / ** * Gets all the designated date list of dates * @param yearMonth * @return * / public static List <the LocalDateTime> getLocalDateTimeList (yearMonth yearMonth) { return getLocalDateList (yearMonth) .stream () .map (localDate -> DateTimeConverterUtil.toLocalDateTime (localDate)) the collect (Collectors.toList ());. } / ** * date Gets a list of all the designated date *@param yearMonthStr yyyy-MM * @return */ public static List<LocalDateTime> getLocalDateTimeList(String yearMonthStr){ return getLocalDateList(yearMonthStr).stream() .map(localDate -> DateTimeConverterUtil.toLocalDateTime(localDate)).collect(Collectors.toList()); } /** * 获取指定年月的所有日期列表 * @param yearMonthStr yyyy-MM * @return */ public static List<Date> getDateList(String yearMonthStr){ returngetLocalDateList (yearMonthStr) .stream () Map (localDate ->. DateTimeConverterUtil.toDate (localDate)) .collect (Collectors.toList ()); } / ** * is determined whether expired, (less than the current year, month, date input) * @param yearMonth * @return * / public static Boolean isExpiry (yearMonth yearMonth) { Objects.requireNonNull (yearMonth, "yearMonth" ); IF (yearMonth.isBefore (YearMonth.now ())) { return to true ; } return to false ; } / ** * Determination has expired, (less than the current year, month, date input) * @param yearMonthStr the MM-YYYY * @return * / public static Boolean isExpiry (String yearMonthStr) { Objects.requireNonNull (yearMonthStr, "yearMonthStr" ); YearMonth yearMonth = YearMonth .parse (yearMonthStr); return isExpiry (yearMonth); }
Test code:
/ ** * yearMonth test * / @Test public void yearMonthTest () { // if expired System.out.println (DateTimeCalculatorUtil.isExpiry ( "2020-03" )); // Gets the specified date list of all dates List < DATE> dateList = DateTimeCalculatorUtil.getDateList ( "2020-03" ); dateList.stream () forEach (DATE. -> { System.out.println (DateTimeFormatterUtil.formatToDateStr (DATE)); }); System.out.println ( "========================" ); // get the list of designated time intervals, including an initial List<Date> dateList2 = DateTimeCalculatorUtil.getDateList(dateList.get(0), dateList.get(dateList.size()-1)); dateList2.stream().forEach(date->{ System.out.println(DateTimeFormatterUtil.formatToDateStr(date)); }); }
Output:
false
2020-03-01
2020-03-02
2020-03-03
2020-03-04
2020-03-05
2020-03-06
2020-03-07
2020-03-08
2020-03-09
2020-03-10
2020-03-11
2020-03-12
2020-03-13
2020-03-14
2020-03-15
2020-03-16
2020-03-17
2020-03-18
2020-03-19
2020-03-20
2020-03-21
2020-03-22
2020-03-23
2020-03-24
2020-03-25
2020-03-26
2020-03-27
2020-03-28
2020-03-29
2020-03-30
2020-03-31
========================
2020-03-01
2020-03-02
2020-03-03
2020-03-04
2020-03-05
2020-03-06
2020-03-07
2020-03-08
2020-03-09
2020-03-10
2020-03-11
2020-03-12
2020-03-13
2020-03-14
2020-03-15
2020-03-16
2020-03-17
2020-03-18
2020-03-19
2020-03-20
2020-03-21
2020-03-22
2020-03-23
2020-03-24
2020-03-25
2020-03-26
2020-03-27
2020-03-28
2020-03-29
2020-03-30
2020-03-31
Source address: https://github.com/xkzhangsan/xk-time