Java8 LocalDateTime和Date相互转换

很想要用Java的时间api，但有时候还是需要转换为Date. 二者的相互转换并不是一步到位那么简单，所以，还是需要记录一下转换的api

Date to LocalDateTime

Date todayDate = new Date();

LocalDateTime ldt = Instant.ofEpochMilli( todayDate.getTime() )
        .atZone( ZoneId.systemDefault() )
        .toLocalDateTime();

System.out.println(ldt);
//2019-05-16T19:22:12.773

LocalDateTime to Date

LocalDateTime localDateTime = LocalDateTime.now();

Date date = Date.from( localDateTime.atZone( ZoneId.systemDefault()).toInstant());

System.out.println(date);
//Thu May 16 19:22:37 CST 2019

DateUtils

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Date;
 
public class DateUtils {
 
    public static Date asDate(LocalDate localDate) {
        return Date.from(localDate.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant());
    }
 
    public static Date asDate(LocalDateTime localDateTime) {
        return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
    }
 
    public static LocalDate asLocalDate(Date date) {
        return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDate();
    }
 
    public static LocalDateTime asLocalDateTime(Date date) {
        return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDateTime();
    }
}