DateUtils - 时间工具类

import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
import java.util.regex.Pattern;

public class DateUtils {

    // 格式：年－月－日 小时：分钟：秒
    public static final String FORMAT_ONE = "yyyy-MM-dd HH:mm:ss";

    //到毫秒
    public static final String FORMAT_SSS = "yyyy-MM-dd HH:mm:ss:SSS";

    // 格式：年－月－日 小时：分钟
    public static final String FORMAT_TWO = "yyyy-MM-dd HH:mm";

    // 格式：年月日 小时分钟秒
    public static final String FORMAT_THREE = "yyyyMMdd-HHmmss";
    // 格式：年－月－日 小时：分钟：秒
    public static final String FORMAT_FOUR = "yyyyMMddHHmmss";
    // 格式：年－月－日
    public static final String LONG_DATE_FORMAT = "yyyy-MM-dd";

    // 格式：月－日
    public static final String SHORT_DATE_FORMAT = "MM-dd";

    // 格式：小时：分钟：秒
    public static final String LONG_TIME_FORMAT = "HH:mm:ss";

    //格式：年-月
    public static final String MONTG_DATE_FORMAT = "yyyy-MM";


    // 年的加减
    public static final int SUB_YEAR = Calendar.YEAR;

    // 月加减
    public static final int SUB_MONTH = Calendar.MONTH;

    // 天的加减
    public static final int SUB_DAY = Calendar.DATE;

    // 小时的加减
    public static final int SUB_HOUR = Calendar.HOUR;

    // 分钟的加减
    public static final int SUB_MINUTE = Calendar.MINUTE;

    // 秒的加减
    public static final int SUB_SECOND = Calendar.SECOND;

    static final String dayNames[] = {"星期日", "星期一", "星期二", "星期三", "星期四",
            "星期五", "星期六"};

    private DateTools() {
    }

    /**
     * 把符合日期格式的字符串转换为日期类型
     */
    public static Date stringtoDate(String dateStr, String format) {
        Date d = null;
        SimpleDateFormat formater = new SimpleDateFormat(format);
        try {
            formater.setLenient(false);
            d = formater.parse(dateStr);
        } catch (Exception e) {
            d = null;
        }
        return d;
    }

    /**
     * 把符合日期格式的字符串转换为日期类型
     */
    public static Date stringtoDate(String dateStr, String format,
                                    ParsePosition pos) {
        Date d = null;
        SimpleDateFormat formater = new SimpleDateFormat(format);
        try {
            formater.setLenient(false);
            d = formater.parse(dateStr, pos);
        } catch (Exception e) {
            d = null;
        }
        return d;
    }

    /**
     * 把日期转换为字符串
     */
    public static String dateToString(Date date, String format) {
        String result = "";
        SimpleDateFormat formater = new SimpleDateFormat(format);
        try {
            result = formater.format(date);
        } catch (Exception e) {
        }
        return result;
    }

    /**
     * 获取当前时间的指定格式
     */
    public static String getCurrDate(String format) {
        return dateToString(new Date(), format);
    }

    /**
     * 获得昨天的指定格式
     *
     * @return
     */
    public static String getYesterDay(String format) {
        Calendar c = Calendar.getInstance();
        c.add(Calendar.DATE, -1);
        return new SimpleDateFormat(format).format(c.getTime());
    }

    /**
     * 获得昨天的开始时间
     *
     * @return
     */
    public static Date getYesterDayStartTime() {
        Calendar c = getYesterDayInstance();
        String yesterdayStart = new SimpleDateFormat("yyyy-MM-dd 00:00:00").format(c.getTime());
        return stringtoDate(yesterdayStart, FORMAT_ONE);
    }

    /**
     * 获得昨天的结束时间
     *
     * @return
     */
    public static Date getYesterDayEndTime() {
        Calendar c = getYesterDayInstance();
        String yesterdayEnd = new SimpleDateFormat("yyyy-MM-dd 23:59:59").format(c.getTime());
        return stringtoDate(yesterdayEnd, FORMAT_ONE);
    }

    /**
     * 日期计算返回String
     *
     * @param dateKind 类型（SUB_DAY...）
     * @param dateStr  日期
     * @param amount   增量
     * @return
     */
    public static String dateSub(int dateKind, String dateStr, int amount) {
        Date date = stringtoDate(dateStr, FORMAT_ONE);
        return dateSub(dateKind, date, amount, FORMAT_ONE);
    }

    /**
     * 日期计算返回String
     *
     * @param dateKind 类型（SUB_DAY...）
     * @param date     日期
     * @param amount   增量
     * @return
     */
    public static String dateSub(int dateKind, Date date, int amount) {
        return dateSub(dateKind, date, amount, FORMAT_ONE);
    }

    /**
     * 日期计算返回String
     *
     * @param dateKind 类型（SUB_DAY...）
     * @param date     日期
     * @param amount   增量
     * @param format   返回格式
     * @return
     */
    public static String dateSub(int dateKind, Date date, int amount, String format) {
        return dateToString(dateSubToDate(dateKind, date, amount), format);
    }

    /**
     * 日期计算返回Date
     *
     * @param dateKind
     * @param date     日期
     * @param amount   增量
     * @return
     */
    public static Date dateSubToDate(int dateKind, Date date, int amount) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(dateKind, amount);
        return calendar.getTime();
    }

    /**
     * 两个日期相减
     *
     * @return 相减得到的秒数
     */
    public static long timeSub(String firstTime, String secTime) {
       Date firstDate = stringtoDate(firstTime, FORMAT_ONE);
       Date secondDate = stringtoDate(secTime, FORMAT_ONE);
       if(firstDate == null || secondDate == null) {
          return -1l;
       }
        long first = firstDate.getTime();
        long second = secondDate.getTime();
        return (second - first) / 1000;
    }

    /**
     * 获得某月的天数
     */
    public static int getDaysOfMonth(String year, String month) {
        int days = 0;
        if (month.equals("1") || month.equals("3") || month.equals("5")
                || month.equals("7") || month.equals("8") || month.equals("10")
                || month.equals("12")) {
            days = 31;
        } else if (month.equals("4") || month.equals("6") || month.equals("9")
                || month.equals("11")) {
            days = 30;
        } else {
            if ((Integer.parseInt(year) % 4 == 0 && Integer.parseInt(year) % 100 != 0)
                    || Integer.parseInt(year) % 400 == 0) {
                days = 29;
            } else {
                days = 28;
            }
        }

        return days;
    }

    /**
     * 获取某年某月的天数
     */
    public static int getDaysOfMonth(int year, int month) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, 1);
        return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
    }

    /**
     * 获得当前日期
     */
    public static int getToday() {
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.DATE);
    }

    /**
     * 获得当前月份
     */
    public static int getToMonth() {
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 获得当前年份
     */
    public static int getToYear() {
        Calendar calendar = Calendar.getInstance();
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 返回日期的天
     */
    public static int getDay(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.DATE);
    }

    /**
     * 返回日期的年
     */
    public static int getYear(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 返回日期的月份，1-12
     */
    public static int getMonth(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 计算两个日期相差的天数，如果date2 > date1 返回正数，否则返回负数
     */
    public static long dayDiff(Date date1, Date date2) {
        return (date2.getTime() - date1.getTime()) / 86400000;
    }

    /**
     * 比较两个日期的年差
     */
    public static int yearDiff(String before, String after) {
        Date beforeDay = stringtoDate(before, LONG_DATE_FORMAT);
        Date afterDay = stringtoDate(after, LONG_DATE_FORMAT);
        return getYear(afterDay) - getYear(beforeDay);
    }

    /**
     * 比较指定日期与当前日期的差
     */
    public static int yearDiffCurr(String after) {
        Date beforeDay = new Date();
        Date afterDay = stringtoDate(after, LONG_DATE_FORMAT);
        return getYear(beforeDay) - getYear(afterDay);
    }

    /**
     * 比较指定日期与当前日期的差long数据类型
     */
    public static long timeDiffCurr(long after) {
        return (new Date().getTime()) - after;
    }

    /**
     * 获取每月的第一周
     */
    public static int getFirstWeekdayOfMonth(int year, int month) {
        Calendar c = Calendar.getInstance();
        c.setFirstDayOfWeek(Calendar.SATURDAY); // 星期天为第一天
        c.set(year, month - 1, 1);
        return c.get(Calendar.DAY_OF_WEEK);
    }

    /**
     * 获取每月的最后一周
     */
    public static int getLastWeekdayOfMonth(int year, int month) {
        Calendar c = Calendar.getInstance();
        c.setFirstDayOfWeek(Calendar.SATURDAY); // 星期天为第一天
        c.set(year, month - 1, getDaysOfMonth(year, month));
        return c.get(Calendar.DAY_OF_WEEK);
    }

    /**
     * 获取当周内第一天的日期
     *
     * @param date
     * @return
     */
    public static Date getFirstWeekdayOfWeek(Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        int dayOfWeek = c.get(Calendar.DAY_OF_WEEK) - 1;
        if (dayOfWeek == 0) {
            dayOfWeek = 7;
        }
        return dateSubToDate(DateTools.SUB_DAY, date, -(dayOfWeek - 1));
    }

    public static Date getLastWeekdayOfWeek(Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        int dayOfWeek = c.get(Calendar.DAY_OF_WEEK) - 1;
        if (dayOfWeek == 0) {
            dayOfWeek = 7;
        }
        return dateSubToDate(DateTools.SUB_DAY, date, (7 - dayOfWeek));
    }

    /**
     * unix时间戳转换北京当前时间
     * @param unixtimestamp unix时间戳
     * @return 时间格式yyyy-MM-dd HH:mm:ss
     */
    public static Date unixtimestampToDate(String unixtimestamp){
        String res;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        long lt = new Long(unixtimestamp)*1000;
        return new Date(lt);
    }

    /**
     * 获得当前日期字符串，格式"yyyy-MM-dd HH:mm:ss"
     *
     * @return
     */
    public static String getNow() {
        Calendar today = Calendar.getInstance();
        return dateToString(today.getTime(), FORMAT_ONE);
    }

    /**
     * 判断日期是否有效,包括闰年的情况
     *
     * @param date YYYY-mm-dd
     * @return
     */
    public static boolean isDate(String date) {
        StringBuffer reg = new StringBuffer(
                "^((\\d{2}(([02468][048])|([13579][26]))-?((((0?");
        reg.append("[13578])|(1[02]))-?((0?[1-9])|([1-2][0-9])|(3[01])))");
        reg.append("|(((0?[469])|(11))-?((0?[1-9])|([1-2][0-9])|(30)))|");
        reg.append("(0?2-?((0?[1-9])|([1-2][0-9])))))|(\\d{2}(([02468][12");
        reg.append("35679])|([13579][01345789]))-?((((0?[13578])|(1[02]))");
        reg.append("-?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))");
        reg.append("-?((0?[1-9])|([1-2][0-9])|(30)))|(0?2-?((0?[");
        reg.append("1-9])|(1[0-9])|(2[0-8]))))))");
        Pattern p = Pattern.compile(reg.toString());
        return p.matcher(date).matches();
    }

    /**
     * 把毫秒转化成日期
     *
     * @param dateFormat(日期格式，例如：MM/ dd/yyyy HH:mm:ss)
     * @param millSec(毫秒数)
     * @return
     */
    public static String longToDate(String dateFormat, Long millSec) {
        SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
        Date date = new Date(millSec);
        return sdf.format(date);
    }

    /**
     * 比较两Date相差几天、几周、几月、几年
     *
     * @param fDate
     * @param oDate
     * @param type
     * @return
     */
    public static int daysOfTwo(Date fDate, Date oDate, int type) {
        long timeLong = 0;
        int dayNum = 0;
        switch (type) {
            case Calendar.HOUR:
                timeLong = oDate.getTime() - fDate.getTime();
                dayNum = (int) ((timeLong / 1000) / 3600);
                return dayNum;
            case Calendar.DAY_OF_YEAR:
                timeLong = oDate.getTime() - fDate.getTime();
                dayNum = (int) (((timeLong / 1000) / 3600) / 24);
                return dayNum;
            case Calendar.WEEK_OF_YEAR:
                timeLong = oDate.getTime() - fDate.getTime();
                dayNum = (int) (((timeLong / 1000) / 3600) / 24 / 7);
                return dayNum;
            case Calendar.MONTH:
                timeLong = oDate.getTime() - fDate.getTime();
                dayNum = (int) (((timeLong / 1000) / 3600) / 24 / 31);
                return dayNum;
            case Calendar.YEAR:
                timeLong = oDate.getTime() - fDate.getTime();
                dayNum = (int) (((timeLong / 1000) / 3600) / 24 / 360);
                return dayNum;
        }
        return 0;
    }

    /**
     * 获取UTC时间 格式：YYYY-MM-DDThh:mm:ssZ
     *
     * @param date
     * @return
     */
    public static String getSolrDate(Date date) {
        SimpleDateFormat sdf1 = new SimpleDateFormat(LONG_DATE_FORMAT);
        SimpleDateFormat sdf2 = new SimpleDateFormat(LONG_TIME_FORMAT);
        String result = sdf1.format(date) + "T" + sdf2.format(date) + "Z";
        return result;
    }

    private static Calendar getYesterDayInstance() {
        Calendar c = Calendar.getInstance();
        c.add(Calendar.DATE, -1);
        return c;
    }

    /**
     * local时间转换成UTC时间
     * @return
     */
    public static String localToUTC() {

        Date localDate = new Date();
        long localTimeInMillis = localDate.getTime();
        /** long时间转换成Calendar */
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(localTimeInMillis);
        /** 取得时间偏移量 */
        int zoneOffset = calendar.get(java.util.Calendar.ZONE_OFFSET);
        /** 取得夏令时差 */
        int dstOffset = calendar.get(java.util.Calendar.DST_OFFSET);
        /** 从本地时间里扣除这些差量，即可以取得UTC时间*/
        calendar.add(java.util.Calendar.MILLISECOND, -(zoneOffset + dstOffset));
        /** 取得的时间就是UTC标准时间 */
        Date utcDate = new Date(calendar.getTimeInMillis());

        return getSolrDate(utcDate);
    }


    /**
     * utc时间转成local时间
     * @param utcTime
     * @return
     */
    public static Date utcToLocal(String utcTime) {
        SimpleDateFormat sdf = new SimpleDateFormat(FORMAT_ONE);
        sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
        Date utcDate = null;
        try {
            utcDate = sdf.parse(utcTime);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        sdf.setTimeZone(TimeZone.getDefault());
        Date locatlDate = null;
        String localTime = sdf.format(utcDate.getTime());
        try {
            locatlDate = sdf.parse(localTime);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return locatlDate;
    }

}