关于 jdk1.8 时间处理的方法（实用）

package avg.position.zhangdi;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.Duration;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.Period;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAccessor;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class DateTimeFormat {
public static void main(String[] args) throws ParseException {

    /*java.time包内，有几个比较重要的组件，Instant（时间戳）；LocalDate（日期）；LocalDate（时间）；LocalDateTime（日期时间）；
    ZonedDateTime（带有区域信息的日期时间，比如中国默认使用的是东八区）。Period（如两个日期之间相差的天数）；Druation（两个日期时间之间间隔的秒和纳秒）。*/

    Instant now = Instant.now();
    System.out.println(now.toString());  // 2018-08-06T09:44:13.677Z  (utc时间格式，标准时间格式)
    System.out.println(now.get(ChronoField.MILLI_OF_SECOND)); //毫秒 677
    System.out.println(now.get(ChronoField.MICRO_OF_SECOND)); //微秒 677000
    System.out.println(now.get(ChronoField.NANO_OF_SECOND));  //纳秒 677000000
    System.out.println(ZoneId.systemDefault());  // Asia/Shanghai
    LocalDateTime localDateTime = LocalDateTime.ofInstant(now, ZoneId.systemDefault());
    LocalDate localDate = LocalDate.now();  //
    System.out.println(localDate);  //2018-08-06
    System.out.println(localDateTime); //2018-08-06T17:44:13.677

    // 获得当前日期
    LocalDate localDate1 = LocalDate.now();
    System.out.println(localDate1.toString());
    // 日期加上1天
    LocalDate localDate2 = localDate1.plusDays(1);
    System.out.println(localDate2.toString());
    // 日期加上一周
    LocalDate localDate3 = localDate1.plusWeeks(1);
    System.out.println(localDate3);
    // 计算当前年的第52天是几月几号
    System.out.println("今年的第52天 = " + localDate1.withDayOfYear(52));

    // 字符串转日期
    DateTimeFormatter strToDateFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    TemporalAccessor dateTemporal = strToDateFormatter.parse("2017-01-01 13:00:00");
    LocalDate date = LocalDate.from(dateTemporal);
    System.out.println(date);
    LocalDateTime dateTime = LocalDateTime.parse("2017-01-01 13:00:00", strToDateFormatter);
    System.out.println(dateTime.toString());

    // 格式化日期
    LocalDateTime localDateTime1 = LocalDateTime.now();
    DateTimeFormatter dateToStrFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    String dateStr = dateToStrFormatter.format(localDateTime1);
    System.out.println(dateStr);

    // 只处理时间
    LocalTime localTime = LocalTime.now();
    System.out.println("local time = " + localTime);
    System.out.println("plus 12 hours = " + localTime.plusHours(12));

    /*Period
    Period代表的是两个日期之间的天、月、年数差值，当然，我们也可以直接使用日期中的until方法来完成同样的效果。*/

    LocalDate startDate = LocalDate.now();
    LocalDate endDate = startDate.plusDays(1);

    Period period = Period.between(startDate, endDate);
    System.out.println("间隔的天数" + period.getDays());
    System.out.println("间隔的月数:" + period.getMonths());
    System.out.println("间隔的年数:" + period.getYears());

    // 直接使用日期类中的方法计算日期间隔
    long days = startDate.until(endDate, ChronoUnit.DAYS);
    System.out.println("间隔的天数:" + days);
    long weeks = startDate.until(endDate, ChronoUnit.WEEKS);
    System.out.println("间隔的周数:" + weeks);

    /*Duration表示的是两个日期时间间隔的秒以及纳秒数。*/
    LocalDateTime start = LocalDateTime.now();
    LocalDateTime end = start.plusDays(1);
    Duration duration = Duration.between(start, end);
    System.out.println("间隔的秒数:" + duration.get(ChronoUnit.SECONDS));
    //System.out.println("间隔的毫秒数:" + duration.get(ChronoUnit.MICROS));
    System.out.println("间隔的纳秒数:" + duration.get(ChronoUnit.NANOS));

    ///////////////////////////////
    DateTimeFormatter fmt = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

    String dateTimeF = LocalDateTime.now().format(fmt); //将当前时间转换为  2017-10-19 10:25:36
    //将时间装换为long值      时间戳
    long currentTime = LocalDateTime.parse(dateTimeF,fmt).atZone(ZoneId.of("Asia/Shanghai")).toInstant().toEpochMilli();
    System.out.println("时间戳:"+currentTime);
    //将long转为格式化时间字符串
    String timeNow = fmt.format(LocalDateTime.ofInstant(Instant.ofEpochMilli(currentTime),ZoneId.of("Asia/Shanghai")));
    System.out.println("时间:"+timeNow);

   /* Date转LocalDate：*/
    Date date11 = new Date();
    LocalDate localDate11 = date11.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
    System.out.println(localDate11);
  /*  LocalDate 转 Date:*/
    LocalDateTime localDateTime22 = LocalDateTime.now();
    ZoneId zoneId = ZoneId.systemDefault();
    ZonedDateTime zdt = localDateTime22.atZone(zoneId);
    Date dateType = Date.from(zdt.toInstant());
    //Date dateType = Date.from(localDateTime22.atZone(ZoneId.systemDefault()).toInstant());
    System.out.println("LocalDateTime = " + localDateTime22);
    System.out.println("Date = " + dateType);

    //jdk 1.7
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    SimpleDateFormat sdf2 = new SimpleDateFormat("MM/dd/yyyy");
    Date date33 = sdf.parse("2018-08-08");
    String aaa = sdf2.format(date33);
    System.out.println(aaa);
}

    public static List getDateArrayList(String startTime, String endTime) throws ParseException{

           List dateArrayList = new ArrayList();
              SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
               long stime=sdf.parse(startTime).getTime();
               long etime=sdf.parse(endTime).getTime();
               while(stimeetime){
                String time=sdf.format(new Date(stime));
                dateArrayList.add(time);
                stime += 24*60*60*1000;
               }
               return dateArrayList;
           }

}

Original: https://www.cnblogs.com/zhaoyan001/p/12182873.html
Author: 程序猿001
Title: 关于 jdk1.8 时间处理的方法（实用）