Java8新特性之一、时间日期API

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);
    }