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);	}