Java编程时间日期API实例解析

package com.effective.common.base.date;
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.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.util.Date;
/**
 * 日期工具类
 * @author yanweiqi
 * @since 2016-5-6
 *
 */
public class LocalDateUtils {
	private static ZoneId zone = ZoneId.systemDefault();
	/**
   * 字符串转Date
   * @param date
   * @return
   * @throws Exception
   */
	public static Date convertToDate(String date) throws Exception{
		LocalDate localDate = null;
		if(null == date){
			throw new NullPointerException("date isn't null");
		} else {
			localDate = LocalDate.parse(date);
			return convertToDate(localDate);
		}
	}
	/**
   * 字符串转LocalDateTime
   * @param date
   * @return localDateTime
   */
	public static LocalDateTime convertToLocalDateTime(String date){
		LocalDateTime localDateTime = null;
		if(null == date){
			throw new NullPointerException("date isn't null");
		} else {
			localDateTime = LocalDateTime.parse(date);
			return localDateTime;
		}
	}
	/**
   * LocalDate转Date
   * @param localDate
   * @return Date
   */
	public static Date convertToDate(LocalDate localDate){
		Instant instant = localDate.atStartOfDay().atZone(zone).toInstant();
		return Date.from(instant);
	}
	/**
   * LocalDate转Date
   * @param localDateTime
   * @return Date
   */
	public static Date convertToDate(LocalDateTime localDateTime){
		Instant instant = localDateTime.atZone(zone).toInstant();
		return Date.from(instant);
	}
	/**
   * Date转LocalDate
   * @param date
   * @return localDate
   */
	public static LocalDate convertToLocalDate(Date date){
		Instant instant = date.toInstant();
		return convertToLocalDateTime(instant).toLocalDate();
	}
	/**
   * Date转LocalTime
   * @param date
   * @return localDate
   */
	public static LocalTime convertToLocalTime(Date date){
		Instant instant = date.toInstant();
		return convertToLocalDateTime(instant).toLocalTime();
	}
	/**
   * Date转LocalDatetime
   * @param date
   * @return localDate
   */
	public static LocalDateTime convertToLocalDateTime(Date date){
		Instant instant = date.toInstant();
		return convertToLocalDateTime(instant);
	}
	/**
   * Instant转LocalDateTime
   * @param instant
   * @return
   */
	public static LocalDateTime convertToLocalDateTime(Instant instant){
		return LocalDateTime.ofInstant(instant, zone);
	}
	/**
   * LocalDateTime转Instant
   * @param localDateTime
   * @return
   */
	public static Instant convertToInstant(LocalDateTime localDateTime){
		return localDateTime.atZone(zone).toInstant();
	}
	/**
   * LocalDate转Instant
   * @param localDate
   * @return
   */
	public static Instant convertToInstant(LocalDate localDate){
		return localDate.atStartOfDay(zone).toInstant();
	}
	/**
   * LocalDate转LocalDateTime
   * @param localDate
   * @return LocalDateTime
   */
	public static LocalDateTime convertToLocalDateTime(LocalDate localDate){
		return localDate.atStartOfDay();
	}
	/**
   * 日周期格式化
   * @param localDateTime
   * @param formatStyle
   * @return
   */
	public static String formatter(LocalDateTime localDateTime, String formatStyle){
		return DateTimeFormatter.ofPattern(formatStyle).format(localDateTime);
	}
	/**
   * 设置年
   * @param sourceDate
   * @param year
   * @return LocalDateTime
   */
	public static LocalDateTime setYear(LocalDateTime sourceDate, Integer year){
		return sourceDate.withYear(year);
	}
	/**
   * 设置月
   * @param sourceDate
   * @param month
   * @return LocalDateTime
   */
	public static LocalDateTime setMonth(LocalDateTime sourceDate, Integer month){
		return sourceDate.withMonth(month);
	}
	/**
   * 设置天
   * @param sourceDate
   * @param month
   * @return LocalDateTime
   */
	public static LocalDateTime setDayOfMonth(LocalDateTime sourceDate, Integer dayOfMonth){
		return sourceDate.withDayOfMonth(dayOfMonth);
	}
	/**
   * 设置小时
   * @param sourceDate
   * @param hour
   * @return
   */
	public static LocalDateTime setHour(LocalDateTime sourceDate,Integer hour){
		return sourceDate.withHour(hour);
	}
	/**
   * 设置分钟
   * @param sourceDate
   * @param minute
   * @return
   */
	public static LocalDateTime setMinute(LocalDateTime sourceDate,Integer minute){
		return sourceDate.withMinute(minute);
	}
	/**
   * 设置秒
   * @param sourceDate
   * @param second
   * @return
   */
	public static LocalDateTime setSecond(LocalDateTime sourceDate,Integer second){
		return sourceDate.withSecond(second);
	}
	/**
   * 修改年月日
   * @param sourceDate
   * @param year
   * @param month
   * @param dayOfMonth
   * @return
   */
	public static LocalDateTime setYMD(LocalDateTime sourceDate, Integer year, Integer month, Integer dayOfMonth) {
		return sourceDate.withYear(year).withMonth(month).withDayOfMonth(dayOfMonth);
	}
	/**
   * 修改时分秒
   * @param sourceDate
   * @param hour
   * @param minute
   * @param second
   * @return
   */
	public static LocalDateTime setHMS(LocalDateTime sourceDate,Integer hour, Integer minute, Integer second) {
		return sourceDate.withHour(hour).withMinute(minute).withSecond(second);
	}
	/**
   * 计算相差的天数
   * @param beginDate
   * @param endDate
   * @return
   */
	public static int getInteverDays(LocalDate beginDate,LocalDate endDate){
		Period period = Period.between(beginDate, endDate);
		return period.getDays();
	}
	/**
   * 日期加减
   * @param num 数量
   * @param unit 单位
   * @param LocalDate 原日期
   * @return LocalDate 增加后的日期
   */
	@SuppressWarnings("static-access")
	  public static LocalDate addLocalDate(long num,ChronoUnit unit,final LocalDate localDate){
		LocalDate resultDate;
		if(num > 0){
			resultDate = localDate.now().plus(num, unit);
		} else {
			resultDate = localDate.now().minus(Math.abs(num), unit);
		}
		return resultDate;
	}
	/**
   * 日期时分秒加
   * @param num 数量
   * @param unit 单位
   * @param localDateTime 原日期
   * @return LocalDateTime 增加后的日期
   */
	@SuppressWarnings("static-access")
	  public static LocalDateTime addLocalDateTime(long num,ChronoUnit unit,LocalDateTime localDateTime){
		LocalDateTime resultDateTime;
		if(num > 0){
			resultDateTime = localDateTime.now().plus(num, unit);
		} else {
			resultDateTime = localDateTime.now().minus(Math.abs(num),unit);
		}
		return resultDateTime;
	}
	/**
   * 时分秒加减
   * @param num 数量
   * @param unit 单位
   * @param localTime 原日期
   * @return LocalDateTime 增加后的日期
   */
	@SuppressWarnings("static-access")
	  public static LocalTime addLocalTime(long num,ChronoUnit unit,LocalTime localTime){
		LocalTime resultTime;
		if(num > 0){
			resultTime = localTime.now().plus(num, unit);
		} else {
			resultTime = localTime.now().minus(Math.abs(num), unit);
		}
		return resultTime;
	}
	public static void main(String[] args){
		LocalDateTime time = LocalDateTime.now();
		String rr = formatter(time, "yyyy-MM-dd HH:mm:ss");
		System.out.println(rr);
		LocalDateTime time2 = addLocalDateTime(-2, ChronoUnit.HOURS, time);
		String yy = formatter(time2, "yyyy-MM-dd HH:mm:ss");
		System.out.println(yy);
	}