java8中的LocalDate，LocalTime，LocalDateTime与Date的转换和使用

package com.wangwenjun.java8; 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.ZonedDateTime; import java.time.format.DateTimeFormatter; import java.util.Date; public class LocalDateUtil { private final static String FORMAT_PATTERN1="yyyy-MM-dd HH:mm:ss"; private final static String FORMAT_PATTERN2="yyyyMMddHHmmss"; private final static String FORMAT_PATTERN3="yyyy-MM-dd"; private final static String FORMAT_PATTERN4="yyyyMMdd"; public static void main(String[] args) { Date date1=new Date(); try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println(localDateFormat(LocalDate.now(),FORMAT_PATTERN3)); System.out.println(localDateTimeFormat(LocalDateTime.now(),FORMAT_PATTERN1)); System.out.println(localDateTimeFormat(LocalDateTime.now(),FORMAT_PATTERN2)); System.out.println(localDateTimeToDate(LocalDateTime.now())); System.out.println(dateFormat(new Date(),FORMAT_PATTERN4)); System.out.println(minusToMillsLocalDateTime(LocalDateTime.now(),LocalDateTime.now().minusSeconds(1))); System.out.println(minusToMillsDate(date1,new Date())); System.out.println(localDateParse("2018-06-12",FORMAT_PATTERN3)); System.out.println(localDateTimeParse("2018-06-12 16:04:43",FORMAT_PATTERN1)); Period p=periodDate(date1,new Date()); System.out.println("year:"+p.getYears()+"month:"+p.getMonths()+"day:"+p.getDays()); System.out.println("----------------------------------------------------------------"); Date date2=localDateToDate(LocalDate.now().minusMonths(1).minusDays(2)); Date date3=localDateToDate(LocalDate.now()); Period p2=periodDate(date2,date3); System.out.println("year:"+p2.getYears()+"month:"+p2.getMonths()+"day:"+p2.getDays()); System.out.println("----------------------------------------------------------------"); Period p1=periodLocalDate(LocalDate.now().minusDays(2),LocalDate.now()); System.out.println("year:"+p1.getYears()+"month:"+p1.getMonths()+"day:"+p1.getDays()); } /** * 将localDate 按照一定的格式转换成String * @param localDate * @param pattern * @return */ public static String localDateFormat(LocalDate localDate,String pattern){ return localDate.format(DateTimeFormatter.ofPattern(pattern)); } /** * 将localDateTime 按照一定的格式转换成String * @param localDateTime * @param pattern * @return */ public static String localDateTimeFormat(LocalDateTime localDateTime,String pattern){ return localDateTime.format(DateTimeFormatter.ofPattern(pattern)); } /** * 将String 按照pattern 转换成LocalDate * @param time * @param pattern * @return */ public static LocalDate localDateParse(String time,String pattern){ return LocalDate.parse(time,DateTimeFormatter.ofPattern(pattern)); } /** * 将String 按照pattern 转换成LocalDateTime * @param time * @param pattern * @return */ public static LocalDateTime localDateTimeParse(String time,String pattern){ return LocalDateTime.parse(time,DateTimeFormatter.ofPattern(pattern)); } /** * 将date转换成String * @param date * @param pattern * @return */ public static String dateFormat(Date date,String pattern){ return localDateTimeFormat(dateToLocalDateTime(date),pattern); } /** * 将LocalDate 转换成 Date * @param localDate * @return */ public static Date localDateToDate(LocalDate localDate){ ZoneId zoneId = ZoneId.systemDefault();         ZonedDateTime zdt = localDate.atStartOfDay(zoneId); return Date.from(zdt.toInstant()); } /** * 将LocalDateTime 转换成 Date * @param localDateTime * @return */ public static Date localDateTimeToDate(LocalDateTime localDateTime){ ZoneId zoneId = ZoneId.systemDefault();         ZonedDateTime zdt = localDateTime.atZone(zoneId); return Date.from(zdt.toInstant()); } /** * 将 Date 转换成LocalDate * atZone()方法返回在指定时区从此Instant生成的ZonedDateTime。 * @param date * @return */ public static LocalDate dateToLocalDate(Date date){ Instant instant = date.toInstant();         ZoneId zoneId = ZoneId.systemDefault(); return instant.atZone(zoneId).toLocalDate(); } /** * 将 Date 转换成LocalDateTime * atZone()方法返回在指定时区从此Instant生成的ZonedDateTime。 * @param date * @return */ public static LocalDateTime dateToLocalDateTime(Date date){ Instant instant = date.toInstant();         ZoneId zoneId = ZoneId.systemDefault(); return instant.atZone(zoneId).toLocalDateTime(); } /** * 计算两个LocalDateTime 之间的毫秒数 * @param time1 * @param time2 * @return */ public static Long minusToMillsLocalDateTime(LocalDateTime time1,LocalDateTime time2){ return Duration.between(time1, time2).toMillis(); } /** * 计算两个LocalTime 之间的毫秒数 * @param time1 * @param time2 * @return */ public static Long minusToMillsLocalTime(LocalTime time1,LocalTime time2){ return Duration.between(time1, time2).toMillis(); } /** * 计算两个LocalDate 之间的毫秒数 * @param time1 * @param time2 * @return */ public static Long minusToMillsLocalDate(LocalDate time1,LocalDate time2){ return Duration.between(time1, time2).toMillis(); } /** * 计算两个LocalDate 之间的Period * @param time1 * @param time2 * @return */ public static Period periodLocalDate(LocalDate time1,LocalDate time2){ return Period.between(time1,time2); } /** * 计算两个Date 之间的Period * @param date1 * @param date2 * @return */ public static Period periodDate(Date date1,Date date2){ return periodLocalDate(dateToLocalDate(date1),dateToLocalDate(date2)); } /** * 计算两个Date之间的 Period * @param time1 * @param time2 * @return */ public static Long minusToMillsDate(Date time1,Date time2){ return minusToMillsLocalDateTime(dateToLocalDateTime(time1),dateToLocalDateTime(time2)); } }