LocalDate&LocalDateTime常用API互相转换

文章目录

1. 1. LocalDateTime to String(将LocalDateTime 转为自定义的时间格式字符串
2. 2. timestamp to LocalDateTime(将long类型的timeStamp转为LocalDateTime)
3. 3. LocalDateTime to timestamp(将LocalDateTime转为long类型的timeStamp)
4. 4. LocalDateTime to Date(将LocalDateTime to Date)
5. 5. String to 自定义格式(Formatter)的LocalDateTime(将时间字符串转为自定义格式的LocalDateTime)
6. 6. Date to LocalDateTime(将Date转为LocalDateTime)
7. 7. Date to LocalDate（将Date 转为 LocalDate）
8. 8. LocalDate to Date
9. 9. Date to LocalTime(将 Date 转为 LocalTime)
10. 10. LocalTime to Date
11. 11. 获取任意日期

在平常时开发过程中，总有很多奇奇怪怪的时间需要互相转换，比如 Date to String , Date to DateTime , String to Date , String to DateTime ,Date to TimeStamp等等……,中间就算对JavaApi再熟悉也难免会搞混，还不如做一些简单的记录，方便日后需要用到之时直接复制出来使用即可。

LocalDateTime to String(将LocalDateTime 转为自定义的时间格式字符串

public static String localDateTimeToString(LocalDateTime localDateTime, String format) 
{
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern(format);
    return localDateTime.format(formatter);
}

timestamp to LocalDateTime(将long类型的timeStamp转为LocalDateTime)

public static LocalDateTime timestampToLocalDateTime(long timestamp) 
{
    Instant instant = Instant.ofEpochMilli(timestamp);
    ZoneId zone = ZoneId.systemDefault();
    return LocalDateTime.ofInstant(instant, zone);
}

LocalDateTime to timestamp(将LocalDateTime转为long类型的timeStamp)

public static long localDateTimeToTimestamp(LocalDateTime localDateTime) 
{
    ZoneId zone = ZoneId.systemDefault();
    Instant instant = localDateTime.atZone(zone).toInstant();
    return instant.toEpochMilli();
}

LocalDateTime to Date(将LocalDateTime to Date)

public static Date localDateTimeToDate(LocalDateTime localDateTime) 
{
    ZoneId zone = ZoneId.systemDefault();
    Instant instant = localDateTime.atZone(zone).toInstant();
    return Date.from(instant);
}

String to 自定义格式(Formatter)的LocalDateTime(将时间字符串转为自定义格式的LocalDateTime)

public static LocalDateTime parseStringToDateTime(String time, String format) 
{
    DateTimeFormatter df = DateTimeFormatter.ofPattern(format);
    return LocalDateTime.parse(time, df);
}

Date to LocalDateTime(将Date转为LocalDateTime)

public static LocalDateTime dateToLocalDateTime(Date date) 
{
    Instant instant = date.toInstant();
    ZoneId zone = ZoneId.systemDefault();
    return LocalDateTime.ofInstant(instant, zone);
}

Date to LocalDate（将Date 转为 LocalDate）

public static LocalDate dateToLocalDate(Date date) 
{
    Instant instant = date.toInstant();
    ZoneId zone = ZoneId.systemDefault();
    LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);
    return localDateTime.toLocalDate();
}

LocalDate to Date

public static Date localDateToDate(LocalDate localDate) 
{
    ZoneId zone = ZoneId.systemDefault();
    Instant instant = localDate.atStartOfDay().atZone(zone).toInstant();
    return Date.from(instant);
}

Date to LocalTime(将 Date 转为 LocalTime)

public static LocalTime dateToLocalTime(Date date) 
{
    Instant instant = date.toInstant();
    ZoneId zone = ZoneId.systemDefault();
    LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);
    return localDateTime.toLocalTime();
}

LocalTime to Date

public static Date localTimeToDate(LocalTime localTime , LocalDate localDate) 
{
    LocalDateTime localDateTime = LocalDateTime.of(localDate, localTime);
    ZoneId zone = ZoneId.systemDefault();
    Instant instant = localDateTime.atZone(zone).toInstant();
    return Date.from(instant);
}

获取任意日期

public static LocalDate anyDay(LocalDate localDate) 
{
    /**
        * 当月第一天-写法1
        */
    //第一天传入1，第二天2，第三天3，第四天4，第五天5,......
    LocalDate dayOfMonth = localDate.withDayOfMonth(2);
    /**
        * 当月第一天-写法2
        */
    LocalDate with = localDate.with(TemporalAdjusters.firstDayOfMonth());
    //当月最后一天
    LocalDate lastDate = localDate.with(TemporalAdjusters.lastDayOfMonth());

    //下一天
    LocalDate plusDays = dayOfMonth.plusDays(1);
    //前一天
    LocalDate minusDays = dayOfMonth.minusDays(1);

    // 取2014年1月第一个周一
    LocalDate firstMondayOf2014 = LocalDate.parse("2014-01-01").with(TemporalAdjusters.firstInMonth(DayOfWeek.MONDAY));

    return dayOfMonth;
}