直接通过一个例子，说明JDK8新增的日期的使用。
import java.time.*;
import java.time.format.DateTimeFormatter;
import java.util.Date;public class TimeConfig {public static void main(String[] args) {// Date 与 Instant 相互转换Date date = new Date();Instant instant = date.toInstant();date = Date.from(instant);// Insant 和 LocalDateTime 转换LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, ZoneId.systemDefault());System.out.println(localDateTime.toString());// LocalDateTime 格式化DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");System.out.println(localDateTime.format(dtf));// 字符串和 LocalDateTime 转换String dateTimeStr = "2020-05-01 14:20:30";localDateTime = LocalDateTime.parse(dateTimeStr, dtf);System.out.println(localDateTime);//Instant 和 LocalDate 转换LocalDate localDate = LocalDateTime.ofInstant(instant, ZoneId.systemDefault()).toLocalDate();dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd");System.out.println(localDate.format(dtf));// 字符串和 LocalDateTime 转换String dateStr = "2020-05-01";localDate = LocalDate.parse(dateStr, dtf);System.out.println(localDate);//Instant 和 LocalTime 转换LocalTime localTime = LocalDateTime.ofInstant(instant, ZoneId.systemDefault()).toLocalTime();dtf = DateTimeFormatter.ofPattern("HH:mm:ss");System.out.println(localTime.format(dtf));// 字符串和 LocalDateTime 转换String timeStr = "14:20:30";localTime = LocalTime.parse(timeStr, dtf);System.out.println(localTime);}
}