时间工具类

package com.hq.schoolcj.util;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
public class DateUtils {
    /**
     * 时间格式(yyyy-MM-dd)
     */
    public final static String DATE_PATTERN = "yyyy-MM-dd";
    public final static String DATE_PATTERN_FOR_SECOND = "yyyy-MM-dd HH:mm:ss";
    public final static String MM_DD_HH_MM = "MM月dd日 HH:mm";
    public final static String MM_DD = "MM-dd";
    public final static String HH_MM = "HH:mm";
    public static final String DEFUALT_LONG_TIME_FORMAT = "yyyyMMddHHmmss";
    public static String format(Date date) {
        return format(date, DATE_PATTERN);
    }
    /**
     * 计算两个日期的相差月份
     * @param startDate 开始时间
     * @param endDate 结束时间
     * @return
     */
    public static Integer getDifMonth(Date startDate, Date endDate){
        if (startDate == null || endDate == null) {
            return 0;
        }
        Calendar start = Calendar.getInstance();
        Calendar end = Calendar.getInstance();
        start.setTime(startDate);
        end.setTime(endDate);
        int result = end.get(Calendar.MONTH) - start.get(Calendar.MONTH);
        int month = (end.get(Calendar.YEAR) - start.get(Calendar.YEAR)) * 12;
        return Math.abs(month + result);
    }
    /**
     * 日期转字符串
     *
     * @param date
     * @param pattern
     * @return
     */
    public static String format(Date date, String pattern) {
        if (date != null) {
            SimpleDateFormat df = new SimpleDateFormat(pattern);
            return df.format(date);
        }
        return null;
    }
    /**
     * 日期字符串转时间戳
     *
     * @param dateStr
     * @return
     */
    public static Integer transForMilliSecond(String dateStr) {
        Date date = DateUtils.formatDate(dateStr);
        return date == null ? null : DateUtils.transForMilliSecond(date);
    }
    /**
     * 日期字符串转日期
     *
     * @param string
     * @param pattern
     * @return
     */
    public static Date formatDate(String string, String pattern) {
        if (StringUtils.isNotBlank(string)) {
            try {
                return new SimpleDateFormat(pattern).parse(string);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
    /**
     * 字符串转日期
     *
     * @param string
     * @return
     */
    public static Date formatDate(String string) {
        return formatDate(string, DATE_PATTERN);
    }
    /**
     * 日期转时间戳 (秒)
     *
     * @param date
     * @return
     */
    public static Integer transForMilliSecond(Date date) {
        if (date == null) {
            return null;
        }
        return (int) (date.getTime() / 1000);
    }
    /**
     * 时间戳转日期字符串"yyyy-MM-dd"
     *
     * @param ms
     * @return
     */
    public static String transForDate(Integer ms) {
        String str = "";
        if (ms != null) {
            long msl = (long) ms * 1000;
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            if (ms != null) {
                try {
                    str = sdf.format(msl);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        return str;
    }
    /**
     * 时间戳转日期字符串"yyyy-MM-dd"或"yyyy-MM-dd HH:mm:ss"
     *精确到毫秒的字符串
     * @param seconds
     * @return
     */
    public static String transForDate(String seconds, String pattern) {
        if(seconds == null || seconds.isEmpty() || seconds.equals("null")){
            return "";
        }
        if(pattern == null || pattern.isEmpty()){
            pattern = "yyyy-MM-dd HH:mm:ss";
        }
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        return sdf.format(new Date(Long.valueOf(seconds)));
    }
    /**
     * 订单有效期,获取当前时间完后day天后的时间
     *
     * @param day 推移时间
     * @return 推移后的时间
     */
    public static Date orderDateValidity(Long day) {
        return getDateAfter(new Date(), day.intValue());
    }
    /***
     *
     * @param d
     *            :Base Date
     * @param day
     *            :Delayed days
     * @return
     */
    public static java.util.Date getDateAfter(Date d, int day) {
        Calendar now = Calendar.getInstance();
        now.setTime(d);
        now.set(Calendar.DATE, now.get(Calendar.DATE) + day);
        return now.getTime();
    }
    /**
     * 给时间加上几个小时
     *
     * @param date 当前时间 格式：yyyy-MM-dd HH:mm:ss
     * @param hour 需要加的时间
     * @return
     */
    public static String addDateHour(Date date, int hour) {
        if (date == null) {
            return null;
        }
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.HOUR_OF_DAY, hour);
        date = cal.getTime();
        return format(date, DEFUALT_LONG_TIME_FORMAT);
    }
    /**
     * 获取现在时间
     *
     * @return 返回时间类型 yyyy-MM-dd HH:mm:ss
     */
    public static Date getNowDate() {
        Date currentTime = new Date();
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateString = formatter.format(currentTime);
        ParsePosition pos = new ParsePosition(8);
        Date currentTime_2 = formatter.parse(dateString, pos);
        return currentTime_2;
    }
    /**
     * 得到现在时间
     *
     * @return
     */
    public static Date getNow() {
        Date currentTime = new Date();
        return currentTime;
    }
    /*
     * 把时间戳装换为时间字符串
     *
     * */
    public static String getDateString4LongTime(Long timeStamp) {
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
        return formatter.format(new Date(timeStamp));
    }
    public static String dateToString(Date date) {
        SimpleDateFormat sdf = new SimpleDateFormat(DATE_PATTERN_FOR_SECOND);
        return sdf.format(date);
    }
    public static Date stringToDate(String date, String pattern) {
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        try {
            return sdf.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return new Date();
    }
    /***
     *
     * @param d : 基准时间
     * @param day : 几天前
     * @return
     */
    public static Date getDateBefore(Date d, int day) {
        Calendar now = Calendar.getInstance();
        now.setTime(d);
        now.set(Calendar.DATE, now.get(Calendar.DATE) - day);
        return now.getTime();
    }
    public static Date parse(String string, String pattern) {
        if (StringUtils.isNotBlank(string)) {
            try {
                return new SimpleDateFormat(pattern).parse(string);
            } catch (ParseException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
    public static Date parse(String string) {
        return parse(string, DATE_PATTERN);
    }
    /**
     * 毫秒转化为xx小时xx分钟
     *
     * @param longTime
     * @return
     */
    public static String longTimeToString(Long longTime) {
        if (longTime == null || longTime == 0L) {
            return "";
        }
        int hour = (int) (longTime / (1000 * 60 * 60));
        int min = (int) ((longTime % (1000 * 60 * 60)) / (1000 * 60));
        if (hour < 1) {
            return min + "分钟";
        } else if (hour >= 1 && min == 0) {
            return hour + "小时";
        } else if (hour >= 1 && min > 0) {
            return hour + "小时" + min + "分钟";
        }
        return "";
    }
    /**
     * 日期转化为String
     *
     * @param date
     * @return date string
     * @author xuyidong
     */
    public static String toString(Date date) {
        if (null == date) {
            return null;
        }
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US);
            return sdf.format(date);
        } catch (Exception e) {
            return null;
        }
    }
    /**
     * 指定日期加指定天数
     *
     * @param date
     * @param dayNum
     * @return
     */
    public static String convertDate(Date date, int dayNum) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DATE, dayNum);
        Date date2 = calendar.getTime();
        String dateFormat = sdf.format(date2);
        return dateFormat;
    }
    /**
     * 当前时间添加时间
     * @param type 1代表 日  2代表 月  3代表 年
     * @param num 数量
     * @return
     */
    public static Date convertDate(int type,Integer num){
        if(num==null){
            num=0;
        }
        SimpleDateFormat sdf = new SimpleDateFormat(DATE_PATTERN_FOR_SECOND);
        Date nowDate = new Date();
        try{
            nowDate=sdf.parse(sdf.format(nowDate));
        }catch (Exception e){
        }
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(nowDate);
        if(type==1){
            calendar.add(Calendar.DATE, num);
        }else if(type==2){
            calendar.add(Calendar.MONTH, num);
        }else if(type==3){
            calendar.add(Calendar.YEAR, num);
        }
        Date date2 = calendar.getTime();
        return date2;
    }
    public static void main(String[] args) {
//        Date a = formatDate("2019-12-27", "yyyy-MM-dd");
//        Date b = formatDate("2020-01-11", "yyyy-MM-dd");
//        Integer difMonth = getDifMonth(a, b);
//        System.out.println(difMonth);
//        int i = new Date() - formatDate("2019-12-07 17:30:);
    }
    /**
     * Date 转化为jdk8 LocalDate
     *
     * @param date
     * @return LocalDate
     * @author chen xin yu
     * @date 2019-09-02 20:05
     */
    public static LocalDate dateToLocalDate(Date date) {
        Instant instant = date.toInstant();
        ZoneId zone = ZoneId.systemDefault();
        LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);
        return localDateTime.toLocalDate();
    }
    /**
     * jdk8 LocalDate 转化为 Date
     *
     * @param localDate
     * @return Date
     * @author chen xin yu
     * @date 2019-09-02 20:06
     */
    public static Date LocalDateToDate(LocalDate localDate) {
        ZoneId zone = ZoneId.systemDefault();
        Instant instant = localDate.atStartOfDay().atZone(zone).toInstant();
        return Date.from(instant);
    }
    /**
     * jdk8 LocalDateTime 转化为 Date
     *
     * @param localDateTime
     * @return Date
     * @author chen xin yu
     * @date 2019-09-02 20:06
     */
    public static Date LocalDateTimeToDate(LocalDateTime localDateTime) {
        ZoneId zone = ZoneId.systemDefault();
        Instant instant = localDateTime.atZone(zone).toInstant();
        return Date.from(instant);
    }
    /**
     * Date 转化为jdk8 LocalDateTime
     *
     * @param date
     * @return LocalDate
     * @author chen xin yu
     * @date 2019-09-02 20:05
     */
    public static LocalDateTime dateToLocalDateTime(Date date) {
        Instant instant = date.toInstant();
        ZoneId zone = ZoneId.systemDefault();
        LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zone);
        return localDateTime;
    }
    /**
     * 时间加上指定天数后的日期
     *
     * @param date 时间
     * @param day  增加的天数
     * @return date 返回最终时间零点的毫秒值
     */
    public static Date datePlusDays(Date date, long day) {
        //支付时间
        LocalDateTime localDateTime = DateUtils.dateToLocalDateTime(date);
        //订单有效期截止时间
        LocalDate localDate = localDateTime.plusDays(day).toLocalDate();
        return DateUtils.LocalDateToDate(localDate);
    }
    /**
     * 天数转化为xx年xx月
     *
     * @param day 天数
     * @return
     */
    public static String dayToYearMonth(Long day) {
        if (day == null || day == 0L) {
            return "";
        }
        int year = (int) (day / 365);
        int month = (int) ((day % 365)/30);
        if (year < 1) {
            return month + "个月";
        } else if (year >= 1 && month == 0) {
            return year + "年";
        } else if (year >= 1 && month > 0) {
            return year + "年" + month + "个月";
        }
        return "";
    }
    /**
     * 按照指定格式返回当前时间，如果格式为空，则默认为yyyy-MM-dd
     *
     * @param dateFormat
     * @return
     */
    public static Date strToDate(String date, String dateFormat) {
        if (date == null) {
            return null;
        }
        if (org.apache.commons.lang.StringUtils.isBlank(dateFormat)) {
            if (date.length() > 10) {
                dateFormat = DEFUALT_LONG_TIME_FORMAT;
            } else {
                dateFormat = DATE_PATTERN;
            }
        }
        try {
            SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
            return sdf.parse(date);
        } catch (Exception e) {
            return null;
        }
    }
}