【hutool】使用问题

package cn.hutool.core.date;

public class LocalDateTimeUtil {
	
	public static LocalDateTime of(Date date) {
		if (null == date) {
			return null;
		}

		if (date instanceof DateTime) {
			return of(date.toInstant(), ((DateTime) date).getZoneId());
		}
		return of(date.toInstant());
	}
}

• 方案1

对纯原生的转化方式Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant())进行简单封装。即先使用TemporalAccessorUtil#toInstant(TemporalAccessor)将LocalDateTime转化为Instant（底层就是执行localDateTime.atZone(ZoneId.systemDefault()).toInstant()）

package cn.hutool.core.date;

public class TemporalAccessorUtil extends TemporalUtil{
	
	public static Instant toInstant(TemporalAccessor temporalAccessor) {
		if (null == temporalAccessor) {
			return null;
		}

		Instant result;
		if (temporalAccessor instanceof Instant) {
			result = (Instant) temporalAccessor;
		} else if (temporalAccessor instanceof LocalDateTime) {
			result = ((LocalDateTime) temporalAccessor).atZone(ZoneId.systemDefault()).toInstant();
		} else if (temporalAccessor instanceof ZonedDateTime) {
			result = ((ZonedDateTime) temporalAccessor).toInstant();
		} else if (temporalAccessor instanceof OffsetDateTime) {
			result = ((OffsetDateTime) temporalAccessor).toInstant();
		} else if (temporalAccessor instanceof LocalDate) {
			result = ((LocalDate) temporalAccessor).atStartOfDay(ZoneId.systemDefault()).toInstant();
		} else if (temporalAccessor instanceof LocalTime) {
			// 指定本地时间转换 为Instant，取当天日期
			result = ((LocalTime) temporalAccessor).atDate(LocalDate.now()).atZone(ZoneId.systemDefault()).toInstant();
		} else if (temporalAccessor instanceof OffsetTime) {
			// 指定本地时间转换 为Instant，取当天日期
			result = ((OffsetTime) temporalAccessor).atDate(LocalDate.now()).toInstant();
		} else {
			// issue#1891@Github
			// Instant.from不能完成日期转换
			//result = Instant.from(temporalAccessor);
			result = toInstant(LocalDateTimeUtil.of(temporalAccessor));
		}

		return result;
	}
}

再使用Date#from(Instant)

package java.util;

public class Date implements java.io.Serializable, Cloneable, Comparable {
	
    public static Date from(Instant instant) {
        try {
            return new Date(instant.toEpochMilli());
        } catch (ArithmeticException ex) {
            throw new IllegalArgumentException(ex);
        }
    }
}

• 方案2

DateTime类继承于java.util.Date类，为Date类扩展了众多简便方法，这些方法多是DateUtil静态方法的对象表现形式，使用DateTime对象可以完全替代开发中Date对象的使用。

package cn.hutool.core.date;

public class DateUtil extends CalendarUtil {
	
	public static DateTime date(TemporalAccessor temporalAccessor) {
		return new DateTime(temporalAccessor);
	}
}

• 示例

public class Test {
	public static void main(String[] args) {
        final LocalDateTime localDateTime = LocalDateTime.of(2022, 5, 9, 11, 36);
        final Date date1 = Date.from(TemporalAccessorUtil.toInstant(localDateTime));
        final DateTime date2 = DateUtil.date(localDateTime);
    }
}