该工具类包含了如下功能：

• 日期格式化yyyy-MM-dd
• 日期格式化yyyy-MM-dd HH:mm:ss
• 获取当前日期(yyyy-MM-dd)
• 日期时间毫秒级格式化
• 获取日期星期一日期
• 获取日期星期日日期
• 获取月的第一天
• 获取月的最后一天
• 获取当前年
• 获取当前月份
• 获取当月天数
• 现在是本周中第几天
• 现在是本月中第几天
• 现在是一年中第几天
• 现在是一天中第几小时
• 现在是一年中第几小时
• 一年中第几秒
• 比较日期大小
• Java将Unix时间戳转换成指定格式日期字符串

import java.io.Serializable;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 日期工具类
 * @author MrXiao
 * @version 1.0.0
 */
public class DateUtil implements Serializable {
    private static Logger logger = LoggerFactory.getLogger(DateUtil.class);
    
    /***/
    private static final long serialVersionUID = 1L;

    /**
     * 默认短日期格式
     * yyyy-MM-dd
     */
    public static final String DATE_DEFAULT_FORMAT = "yyyy-MM-dd";
    
    /** 
     * 订单号前缀 yyyyMMddHHmmss
     */
    public static final String DATETIME_ORDER_FORMAT = "yyyyMMddHHmmss";
    /**
     * 默认日期时间格式
     * yyyy-MM-dd HH:mm:ss
     */
    public static final String DATETIME_DEFAULT_FORMAT = "yyyy-MM-dd HH:mm:ss";
    /**
     * 默认时间格式
     * HH:mm:ss
     */
    public static final String TIME_DEFAULT_FORMAT = "HH:mm:ss";
    /**
     * 默认日期短格式
     * yyyyMMdd
     */
    public static final String DATE_DEFAULT_SHORT_FORMAT = "yyyyMMdd";

    /**
     * 默认短日期格格式化
     */
    private static DateFormat dateFormat = new SimpleDateFormat(DATE_DEFAULT_FORMAT);
    /**
     * 默认日期时间格式化
     */
    private static DateFormat dateTimeFormat = new SimpleDateFormat(DATETIME_DEFAULT_FORMAT);
    /**
     * 默认时间格式化
     */
    private static DateFormat timeFormat = new SimpleDateFormat(TIME_DEFAULT_FORMAT);

    /**
     * 日历
     */
    private static Calendar gregorianCalendar = new GregorianCalendar();
    /**
     * 日期正则格式
     */
    private static Map<String, String> dateRegFormat = new HashMap<String, String>();

    /** 锁对象 */
    private static final Object lockObj = new Object();

    /** 存放不同的日期模板格式的sdf的Map */
    private static Map<String, ThreadLocal<SimpleDateFormat>> sdfMap = new HashMap<String, ThreadLocal<SimpleDateFormat>>();
    
    static {
        dateRegFormat.put(
                "^\\d{4}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D*$",
                "yyyy-MM-dd-HH-mm-ss");
        dateRegFormat.put(
                "^\\d{4}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D+\\d{1,2}\\D*$",
                "yyyy-MM-dd-HH-mm-ss");//2017年3月12日 12时05分34秒，2017-03-12 12:05:34，2017/3/12 12:5:34
        dateRegFormat.put("^\\d{4}\\D+\\d{2}\\D+\\d{2}\\D+\\d{2}\\D+\\d{2}$",
                "yyyy-MM-dd-HH-mm");//2017-03-12 12:05
        dateRegFormat.put("^\\d{4}\\D+\\d{2}\\D+\\d{2}\\D+\\d{2}$",
                "yyyy-MM-dd-HH");//2017-03-12 12
        dateRegFormat.put("^\\d{4}\\D+\\d{2}\\D+\\d{2}$", "yyyy-MM-dd");//2017-03-12
        dateRegFormat.put("^\\d{4}\\D+\\d{2}$", "yyyy-MM");//2017-03
        dateRegFormat.put("^\\d{4}$", "yyyy");//2017
        dateRegFormat.put("^\\d{14}$", "yyyyMMddHHmmss");//20170312120534
        dateRegFormat.put("^\\d{12}$", "yyyyMMddHHmm");//201703121205
        dateRegFormat.put("^\\d{10}$", "yyyyMMddHH");//2017031212
        dateRegFormat.put("^\\d{8}$", "yyyyMMdd");//20170312
        dateRegFormat.put("^\\d{6}$", "yyyyMM");//201703
        dateRegFormat.put("^\\d{2}\\s*:\\s*\\d{2}\\s*:\\s*\\d{2}$",
                "yyyy-MM-dd-HH-mm-ss");//13:05:34 拼接当前日期
        dateRegFormat.put("^\\d{2}\\s*:\\s*\\d{2}$", "yyyy-MM-dd-HH-mm");//13:05 拼接当前日期
        dateRegFormat.put("^\\d{2}\\D+\\d{1,2}\\D+\\d{1,2}$", "yy-MM-dd");//16.10.18(年.月.日)
        dateRegFormat.put("^\\d{1,2}\\D+\\d{1,2}$", "yyyy-dd-MM");//30.12(日.月) 拼接当前年份
        dateRegFormat.put("^\\d{1,2}\\D+\\d{1,2}\\D+\\d{4}$", "dd-MM-yyyy");//12.21.2016(日.月.年)
    }
    
    /**
     * ron
     * 解决SimpleDateFormat静态化的坑
     * 返回一个ThreadLocal的sdf,每个线程只会new一次sdf
     * @param pattern
     * @return
     */
    private static SimpleDateFormat getSimpleDateFormat(final String pattern) {
        ThreadLocal<SimpleDateFormat> tl = sdfMap.get(pattern);

        // 双检锁是防止sdfMap这个单例被多次put重复的sdf
        if (tl == null) {
            synchronized (lockObj) {
                tl = sdfMap.get(pattern);
                if (tl == null) {
                   
                    // 使用ThreadLocal<SimpleDateFormat>替代原来直接new SimpleDateFormat
                    tl = new ThreadLocal<SimpleDateFormat>() {

                        @Override
                        protected SimpleDateFormat initialValue() {
                            System.out.println("thread: " + Thread.currentThread() + " init pattern: " + pattern);
                            return new SimpleDateFormat(pattern);
                        }
                    };
                    // 只有Map中还没有这个pattern的sdf才会生成新的sdf并放入map
                    sdfMap.put(pattern, tl);
                }
            }
        }
        return tl.get();
    }
    

    /**
     * TODO 将各种日期格式转为  yyyy-MM-dd HH:mm:ss
     *
     * @param dateStr
     * @return
     * @author MrXiao
     * @date 2017年3月13日 下午6:13:45
     */
    public static String formatDate(String dateStr) {
        String curDate = new SimpleDateFormat(DATE_DEFAULT_FORMAT).format(new Date());
        DateFormat formatter1 = new SimpleDateFormat(DATETIME_DEFAULT_FORMAT);
        DateFormat formatter2;
        String result = "";
        try {
            for (String key : dateRegFormat.keySet()) {
                if (Pattern.compile(key).matcher(dateStr).matches()) {
                    formatter2 = new SimpleDateFormat(dateRegFormat.get(key));
                    if (key.equals("^\\d{2}\\s*:\\s*\\d{2}\\s*:\\s*\\d{2}$")
                            || key.equals("^\\d{2}\\s*:\\s*\\d{2}$")) {//13:05:34 或 13:05 拼接当前日期
                        dateStr = curDate + "-" + dateStr;
                    } else if (key.equals("^\\d{1,2}\\D+\\d{1,2}$")) {//21.1 (日.月) 拼接当前年份
                        dateStr = curDate.substring(0, 4) + "-" + dateStr;
                    }

                    result = formatter1.format(formatter2.parse(dateStr.replaceAll("\\D+", "-")));
                    break;
                }
            }
        } catch (Exception e) {
            System.err.println("-----------------日期格式无效:" + dateStr);
        }
        return result;
    }

    /**
     * 日期格式化
     * @param date  日期格式字符串
     * @param format 日期格式
     * @return
     */
    public static Date formatDate(String date, String format) {
        try {
            return new SimpleDateFormat(format).parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
    /**
     * 日期格式化
     * @date 2017年5月10日 下午2:46:44
     * @param date 日期
     * @param format 日期格式
     * @return
     */
    public static Date formatDate(Date date, String format) {
        String sdate = getDateFormat(date, format);
        return formatDate(sdate, format);
    }
    /**
     * 日期格式化yyyy-MM-dd
     *
     * @param date
     * @return
     */
    public static String getDateFormat(Date date) {
        if(date == null) {
            return null;
        }
        return dateFormat.format(date);
    }

    /**
     * 日期格式化yyyy-MM-dd HH:mm:ss
     *
     * @param date
     * @return
     */
    public static String getDateTimeFormat(Date date) {
        if(date == null) {
            return null;
        }
        return dateTimeFormat.format(date);
    }

    /**
     * 时间格式化
     *
     * @param date
     * @return HH:mm:ss
     */
    public static String getTimeFormat(Date date) {
        if(date == null) {
            return null;
        }
        return timeFormat.format(date);
    }

    /**
     * 日期格式化
     *
     * @param date
     * @param 格式类型
     * @return
     */
    public static String getDateFormat(Date date, String format) {
        if (StringUtil.isNotEmpty(format)) {
            return new SimpleDateFormat(format).format(date);
        }
        return null;
    }

    /**
     * 日期格式化 yyyy-MM-dd
     *
     * @param date
     * @return
     */
    public static Date getDateFormat(String date) {
        try {
            return dateFormat.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 时间格式化 yyyy-MM-dd HH:mm:ss
     *
     * @param date
     * @return
     */
    public static Date getDateTimeFormat(String date) {
        try {
            return dateTimeFormat.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 获取当前日期(yyyy-MM-dd)
     *
     * @param date
     * @return
     */
    public static Date getNowDate() {
        return DateUtil.getDateFormat(dateFormat.format(new Date()));
    }

    /**
     * 日期时间毫秒级格式化
     *
     * @param time 日期
     * @param 格式类型 yyyy-MM-dd HH:mm:ss.SSS
     * @return
     */
    public static String getDateTimeMillisFormat(long time) {
        return getDateTimeMillisFormat(new Date(time)) ;
    }

    /**
     * 日期时间毫秒级格式化
     *
     * @param date 日期
     * @param 格式类型 yyyy-MM-dd HH:mm:ss.SSS
     * @return
     */
    public static String getDateTimeMillisFormat(Date date) {
        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(date);
    }

    /**
     * 获取当前日期星期一日期
     *
     * @return date
     */
    public static Date getFirstDayOfWeek() {
        gregorianCalendar.setFirstDayOfWeek(Calendar.MONDAY);
        gregorianCalendar.setTime(new Date());
        gregorianCalendar.set(Calendar.DAY_OF_WEEK, gregorianCalendar.getFirstDayOfWeek()); // Monday
        return gregorianCalendar.getTime();
    }

    /**
     * 获取当前日期星期日日期
     *
     * @return date
     */
    public static Date getLastDayOfWeek() {
        gregorianCalendar.setFirstDayOfWeek(Calendar.MONDAY);
        gregorianCalendar.setTime(new Date());
        gregorianCalendar.set(Calendar.DAY_OF_WEEK, gregorianCalendar.getFirstDayOfWeek() + 6); // Monday
        return gregorianCalendar.getTime();
    }

    /**
     * 获取日期星期一日期
     *
     * @param 指定日期
     * @return date
     */
    public static Date getFirstDayOfWeek(Date date) {
        if (date == null) {
            return null;
        }
        gregorianCalendar.setFirstDayOfWeek(Calendar.MONDAY);
        gregorianCalendar.setTime(date);
        gregorianCalendar.set(Calendar.DAY_OF_WEEK, gregorianCalendar.getFirstDayOfWeek()); // Monday
        return gregorianCalendar.getTime();
    }

    /**
     * 获取日期星期一日期
     *
     * @param 指定日期
     * @return date
     */
    public static Date getLastDayOfWeek(Date date) {
        if (date == null) {
            return null;
        }
        gregorianCalendar.setFirstDayOfWeek(Calendar.MONDAY);
        gregorianCalendar.setTime(date);
        gregorianCalendar.set(Calendar.DAY_OF_WEEK, gregorianCalendar.getFirstDayOfWeek() + 6); // Monday
        return gregorianCalendar.getTime();
    }

    /**
     * 获取当前月的第一天
     *
     * @return date
     */
    public static Date getFirstDayOfMonth() {
        gregorianCalendar.setTime(new Date());
        gregorianCalendar.set(Calendar.DAY_OF_MONTH, 1);
        return gregorianCalendar.getTime();
    }

    /**
     * 获取当前月的最后一天
     *
     * @return
     */
    public static Date getLastDayOfMonth() {
        gregorianCalendar.setTime(new Date());
        gregorianCalendar.set(Calendar.DAY_OF_MONTH, 1);
        gregorianCalendar.add(Calendar.MONTH, 1);
        gregorianCalendar.add(Calendar.DAY_OF_MONTH, -1);
        return gregorianCalendar.getTime();
    }

    /**
     * 获取指定月的第一天
     *
     * @param date
     * @return
     */
    public static Date getFirstDayOfMonth(Date date) {
        gregorianCalendar.setTime(date);
        gregorianCalendar.set(Calendar.DAY_OF_MONTH, 1);
        return gregorianCalendar.getTime();
    }
    /**
     * Java将Unix时间戳转换成指定格式日期字符串
     * @param timestampString 时间戳 如："1473048265";
     * @param formats 要格式化的格式 默认："yyyy-MM-dd HH:mm:ss";
     *
     * @return 返回结果 如："2016-09-05 16:06:42";
     */
    public static String timeStamp2Date(String timestampStr, String formats) {
        if (StringUtil.isEmpty(formats))
            formats = "yyyy-MM-dd HH:mm:ss";
        Long timestamp = Long.parseLong(timestampStr) * 1000;
        String date = new SimpleDateFormat(formats, Locale.CHINA).format(new Date(timestamp));
        return date;
    }
    /**
     * 获取指定月的最后一天
     *
     * @param date
     * @return
     */
    public static Date getLastDayOfMonth(Date date) {
        gregorianCalendar.setTime(date);
        gregorianCalendar.set(Calendar.DAY_OF_MONTH, 1);
        gregorianCalendar.add(Calendar.MONTH, 1);
        gregorianCalendar.add(Calendar.DAY_OF_MONTH, -1);
        return gregorianCalendar.getTime();
    }

    /**
     * 获取日期前一天
     *
     * @param date
     * @return
     */
    public static Date getDayBefore(Date date) {
        gregorianCalendar.setTime(date);
        int day = gregorianCalendar.get(Calendar.DATE);
        gregorianCalendar.set(Calendar.DATE, day - 1);
        return gregorianCalendar.getTime();
    }

    /**
     * 获取日期后一天
     *
     * @param date
     * @return
     */
    public static Date getDayAfter(Date date) {
        gregorianCalendar.setTime(date);
        int day = gregorianCalendar.get(Calendar.DATE);
        gregorianCalendar.set(Calendar.DATE, day + 1);
        return gregorianCalendar.getTime();
    }

    /**
     * 获取当前年
     *
     * @return
     */
    public static int getNowYear() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.YEAR);
    }

    /**
     * 获取当前月份
     *
     * @return
     */
    public static int getNowMonth() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.MONTH) + 1;
    }

    /**
     * 获取当月天数
     *
     * @return
     */
    public static int getNowMonthDays() {
        Calendar d = Calendar.getInstance();
        return d.getActualMaximum(Calendar.DATE);
    }

    /**
     * 现在是本周中第几天
     * @return
     */
    public static int getNowDayOfWeek() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.DAY_OF_WEEK);
    }
    
    /**
     * 现在是本月中第几天
     * @return
     */
    public static int getNowDayOfMonth() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.DAY_OF_MONTH);
    }
    
    /**
     * 现在是一年中第几天
     * @return
     */
    public static int getNowDayOfYear() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.DAY_OF_YEAR);
    }
    
    /**
     * 现在是一天中第几小时
     * @return
     */
    public static int getNowHourOfDay() {
        Calendar d = Calendar.getInstance();
        return d.get(Calendar.HOUR_OF_DAY);
    }
    /**
     * 现在是一年中第几小时
     * @return
     */
    public static int getNowHourOfYear() {
        int days = getNowDayOfYear();
        int hours = getNowHourOfDay();
        
        return 24 * days + hours;
    }
    

    /**
     * 一年中第几小时
     * 
     * @return
     */
    public static String formatHourOfYear() {
        Calendar d = Calendar.getInstance();
        int day = d.get(Calendar.DAY_OF_YEAR);
        int hour = d.get(Calendar.HOUR_OF_DAY);
        hour = 24 * day + hour;
        return String.format("%04d", hour);
    }

    /**
     * 一年中的第几分钟
     * 
     * @return
     */
    public static String formatMinuteOfYear() {
        Calendar d = Calendar.getInstance();
        int day = d.get(Calendar.DAY_OF_YEAR);
        int hour = d.get(Calendar.HOUR_OF_DAY);
        int minute = d.get(Calendar.MINUTE);
        minute = 60 * 24 * day + 60 * (hour - 1) + minute;
        return String.format("%06d", minute);
    }

    /**
     * 一年中第几秒
     * 
     * @return
     */
    public static String formatSecondOfYear() {
        Calendar d = Calendar.getInstance();
        int day = d.get(Calendar.DAY_OF_YEAR);
        int hour = d.get(Calendar.HOUR_OF_DAY);
        int minute = d.get(Calendar.MINUTE);
        int second = d.get(Calendar.SECOND);
        second = 60 * (60 * 24 * day + 60 * (hour - 1) + 60 * (minute - 1)) + second;
        return String.format("%08d", second);
    }
    
    /**
     * 获取时间段的每一天
     *
     * @param 开始日期
     * @param 结算日期
     * @return 日期列表
     */
    public static List<Date> getEveryDay(Date startDate, Date endDate) {
        if (startDate == null || endDate == null) {
            return null;
        }
        // 格式化日期(yy-MM-dd)
        startDate = DateUtil.getDateFormat(DateUtil.getDateFormat(startDate));
        endDate = DateUtil.getDateFormat(DateUtil.getDateFormat(endDate));
        List<Date> dates = new ArrayList<Date>();
        gregorianCalendar.setTime(startDate);
        dates.add(gregorianCalendar.getTime());
        while (gregorianCalendar.getTime().compareTo(endDate) < 0) {
            // 加1天
            gregorianCalendar.add(Calendar.DAY_OF_MONTH, 1);
            dates.add(gregorianCalendar.getTime());
        }
        return dates;
    }

    /**
     * 获取提前多少个月
     *
     * @param monty
     * @return
     */
    public static Date getFirstMonth(int monty) {
        Calendar c = Calendar.getInstance();
        c.add(Calendar.MONTH, -monty);
        return c.getTime();
    }
    
    /**
     * 
     * TODO 比较日期大小
     * @author MrXiao
     * @date 2017年3月17日 下午5:19:02
     * @param sdate1
     * @param sdate2
     * @return sdate1大于sdate2, 返回 1; </br>
     *      sdate1等于sdate2, 返回 0; </br>
     *      sdate1小于sdate2, 返回 -1; </br>
     */
    public static int compareDate(String sdate1, String sdate2) {
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            Date date1 = df.parse(sdate1);
            Date date2 = df.parse(sdate2);
            if (date1.getTime() > date2.getTime()) {
                return 1;
            } else if (date1.getTime() < date2.getTime()) {
                return -1;
            } else {
                return 0;
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return 0;
    }
    /**
     * 
     * TODO 比较日期大小
     * @author MrXiao
     * @date 2017年3月17日 下午5:25:30
     * @param date1
     * @param sdate
     * @return date1大于sdate, 返回 1; </br>
     *      date1等于sdate, 返回 0; </br>
     *      date1小于sdate, 返回 -1; </br>
     */
    public static int compareDate(Date date1, String sdate) {
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            Date date2 = df.parse(sdate);
            if (date1.getTime() > date2.getTime()) {
                return 1;
            } else if (date1.getTime() < date2.getTime()) {
                return -1;
            } else {
                return 0;
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return 0;
    }
    /**
     * 
     * TODO 比较日期大小
     * @author MrXiao
     * @date 2017年3月17日 下午5:27:17
     * @param date1
     * @param date2
     * @return date1大于date2, 返回 1; </br>
     *      date1等于date2, 返回 0; </br>
     *      date1小于date2, 返回 -1; </br>
     */
    public static int compareDate(Date date1, Date date2) {
        try {
            if (date1.getTime() > date2.getTime()) {
                return 1;
            } else if (date1.getTime() < date2.getTime()) {
                return -1;
            } else {
                return 0;
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return 0;
    }

    /**
     * 
     * TODO 返回日期之间相差的天数
     * @author MrXiao
     * @date 2017年3月17日 下午5:29:49
     * @param smdate
     * @param bdate
     * @return
     */
    public static int daysBetween(String smdate, String bdate) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        long time1 = 0;
        long time2 = 0;

        try {
            cal.setTime(sdf.parse(smdate));
            time1 = cal.getTimeInMillis();
            cal.setTime(sdf.parse(bdate));
            time2 = cal.getTimeInMillis();
        } catch (Exception e) {
            e.printStackTrace();
        }
        long between_days = (time2 - time1) / (1000 * 3600 * 24);
        return Integer.parseInt(String.valueOf(between_days));
    }

    public static int daysBetween(Date dt1, Date dt2) {
        Calendar cal = Calendar.getInstance();
        long time1 = 0;
        long time2 = 0;

        try {
            cal.setTime(dt1);
            time1 = cal.getTimeInMillis();
            cal.setTime(dt2);
            time2 = cal.getTimeInMillis();
        } catch (Exception e) {
            e.printStackTrace();
        }
        long between_days = (time2 - time1) / (1000 * 3600 * 24);
        return Integer.parseInt(String.valueOf(between_days));
    }

    // String日期转Date
    public static Date convertString2Date(String strDate) {
        try {
            return dateTimeFormat.parse(strDate);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return new Date();
    }
    
    /**
     * @param aDate
     * @param pattern: Date format pattern
     * @return
     */
    public static final <T extends Date> String format(T date, String pattern) {
        if(date==null) return null;
        try{
            SimpleDateFormat df = new SimpleDateFormat(pattern,java.util.Locale.CHINA);
            String result = df.format(date);
            return result;
        }catch(Exception e){
            return null;
        }
    }
    
    /**
     * 获取当前日期
     * 
     * @param patten 日期格式，如：yyyy-MM-dd HH:mm:ss
     * @return
     */
    public static String getDateStr(String pattern) {
        String date = getSimpleDateFormat(pattern).format(new Date(System.currentTimeMillis()));
        return date;
    }
    
    
    public static Calendar getTime() {
        Calendar time=Calendar.getInstance();
        return time;
    }
    
    public static Calendar getTime(long timeMillis) {
        Calendar time=getTime();
        time.setTimeInMillis(timeMillis);
        return time;
    }
    public static Date getDate() {
        return getTime().getTime();
    }
    public static Date getDate(long timeMillis) {
        return getTime(timeMillis).getTime();
    }
    
    public static String getYYYYMMDD() {
        return getSimpleDateFormat("yyyyMMdd").format(getDate());
    }
    public static String getYYYYMMDD(long time) {
        return getSimpleDateFormat("yyyyMMdd").format(getDate(time));
    }
    public static String getHHmmss() {
        return getSimpleDateFormat("HHmmss").format(getDate());
    }
    public static String getYYYYMM() {
        return getSimpleDateFormat("yyyyMM").format(getDate());
    }
    public static String getYYYYMM(long timeMillis) {
        return getSimpleDateFormat("yyyyMM").format(getDate(timeMillis));
    }
    public static String getMMDD() {
        return getSimpleDateFormat("MMdd").format(getTime());
    }
    public static String getMMDD(long timeMillis) {
        return getSimpleDateFormat("MMdd").format(getDate(timeMillis));
    }
    public static String getDD(long timeMillis) {
        return getSimpleDateFormat("dd").format(getDate(timeMillis));
    }
    
    /**
     * 日期格式化(String转换为Date)
     * 
     * @param dateStr
     *            日期字符串
     * @param patten
     *            处理结果日期的显示格式，如："YYYY-MM-DD"
     * @return
     */
    public static Date getDateToString(String dateStr, String patten) {
        if(StringUtil.isBlank(dateStr)){
            return null;
        }
        try {
            return getSimpleDateFormat(patten).parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }
    
    /**
     * 转换日期
     * @param date
     * @return
     */
    public static Calendar getCalendar(Date date) {
        if (date == null) {
            return null;
        }
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        return calendar;
    }
    /**
     * 
     * TODO 计算昨天或上周五15点
     * @author xiezb
     * @date 2016年9月22日 上午10:04:48
     * @param date
     * @return 计算昨天或上周五15点
     */
    public static Date calcYesterdayOrLastFriday15OClock(Date date) {
        //某一天
        Date oneDate = date;
        //今天周几
        int weekDay = getWeek(date);        
        //date是周一
        if(weekDay == 1){
            //某一天
            oneDate = addDays(oneDate, -3);
        } else {
            //某一天
            oneDate = addDays(date, -1);
        }
        
        //某一天
        String sOneDay = getDateFormat(oneDate, DATE_DEFAULT_FORMAT);       
        //某一天15点
        String sOneDay15 = sOneDay+" 15:00:00";
        
        return formatDate(sOneDay15, DATETIME_DEFAULT_FORMAT);
    }
    /**
     * 
     * TODO 计算某一天15点
     * @author xiezb
     * @date 2016年9月22日 上午11:58:37
     * @param date 日期
     * @param days 天数
     * @return
     */
    public static Date calcOneDay15OClock(Date date, int days) {
        //某一天
        Date oneDate = addDays(date, days);
        //某一天
        String sOneDay = getDateFormat(oneDate, DATE_DEFAULT_FORMAT);       
        //某一天15点
        String sOneDay15 = sOneDay+" 15:00:00";
        
        return formatDate(sOneDay15, DATETIME_DEFAULT_FORMAT);
    }
    
    /**
     * 年份
     * 
     * @param date
     * @return
     */
    public static int getYear(Date date) {
        if (date == null) {
            return -1;
        }
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.YEAR);
    }

    /**
     * 月份
     * 
     * @param date
     * @return
     */
    public static int getMonth(Date date) {
        if (date == null) {
            return -1;
        }
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.MONTH) + 1;
    }

    /**
     * 本年的第几天
     * 
     * @param date
     * @return
     */
    public static int getDayOfYear(Date date) {
        if (date == null) {
            return -1;
        }
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.DAY_OF_YEAR);
    }

    /**
     * 本月的第几天
     * 
     * @param date
     * @return
     */
    public static int getDayOfMonth(Date date) {
        if (date == null) {
            return -1;
        }
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.DAY_OF_MONTH);
    }

    /**
     * 本周第几天（周几）
     * 
     * @param date
     * @return
     */
    public static int getWeek(Date date) {
        if (date == null) {
            return -1;
        }
        Locale.setDefault(Locale.CHINA);
        Calendar calendar = getCalendar(date);

        return calendar.get(Calendar.DAY_OF_WEEK) - 1;
    }

    /**
     * 返回小时
     * 
     * @param date
     * @return
     */
    public static int getHour(Date date) {
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.HOUR_OF_DAY);
    }

    /**
     * 返回分钟
     * 
     * @param date
     * @return
     */
    public static int getMinute(Date date) {
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.MINUTE);
    }

    /**
     * 返回秒钟
     * 
     * @param date
     * @return
     */
    public static int getSecond(Date date) {
        Calendar calendar = getCalendar(date);
        return calendar.get(Calendar.SECOND);
    }

    /**
     * 返回毫秒
     * 
     * @param date
     * @return
     */
    public static long getMillis(Date date) {
        Calendar calendar = getCalendar(date);
        return calendar.getTimeInMillis();
    }

    /**
     * 返回两个日期之间的相隔毫秒数
     *
     * @param d1
     * @param d2
     * @return
     */
    public static long getMillisBetween(Date d1, Date d2) {
        long s = getCalendar(d1).getTimeInMillis();
        long e = getCalendar(d2).getTimeInMillis();
        return Math.abs(e - s);
    }

    /**
     * 返回两个日期之间的相隔分钟
     *
     * @param d1
     * @param d2
     * @return
     */
    public static long getMiniteBetween(Date d1, Date d2) {
        long s = getCalendar(d1).getTimeInMillis();
        long e = getCalendar(d2).getTimeInMillis();
        return Math.abs(e - s) / (1000 * 60);
    }

    /**
     * 获取两个日期之间的天数：cal2 - cal1
     * 
     * @param cal1
     * @param cal2
     * @return
     */
    public static int getDaysBetween(Calendar cal1, Calendar cal2) {
        boolean flag = true;
        int days = cal2.get(Calendar.DAY_OF_YEAR) - cal1.get(Calendar.DAY_OF_YEAR);
        int year2 = cal2.get(Calendar.YEAR);
        int year1 = cal1.get(Calendar.YEAR);

        if (year2 < year1) {
            flag = false;
        }
        if (year1 != year2) {
            do {
                days += cal1.getActualMaximum(Calendar.DAY_OF_YEAR);
                if (flag) {
                    cal1.add(Calendar.YEAR, 1);
                } else {
                    cal1.add(Calendar.YEAR, -1);
                }
            } while (cal1.get(Calendar.YEAR) != year2);
        }
        if (flag) {
            return days;
        }
        return -days;
    }

    public static int getDaysAbsBetween(Date date1, Date date2) {
        return Math.abs(getDaysBetween(getCalendar(date1), getCalendar(date2)));
    }

    /**
     * 获取两个日期之间的天数：date2 - date1
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static int getDaysBetween(Date date1, Date date2) {
        return getDaysBetween(getCalendar(date1), getCalendar(date2));
    }

    /**
     * 获取两个日期之间相隔月份 cal2 - cal1
     * 
     * @param cal1
     * @param cal2
     * @return
     */
    public static int getMonthsBetween(Calendar cal1, Calendar cal2) {
        int months = cal2.get(Calendar.MONTH) - cal1.get(Calendar.MONTH);
        boolean flag = true;

        int year2 = cal2.get(Calendar.YEAR);
        int year1 = cal1.get(Calendar.YEAR);

        if (year2 < year1)
            flag = false;
        if (year1 != year2) {
            do {
                months += cal1.getActualMaximum(Calendar.MONTH) + 1;
                if (flag)
                    cal1.add(Calendar.YEAR, 1);
                else
                    cal1.add(Calendar.YEAR, -1);
            } while (cal1.get(Calendar.YEAR) != year2);
        }
        if (flag) {
            return months;
        }
        return -months;
    }

    /**
     * 获取两个日期相隔的月份 date2 - date1
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static int getMonthsBetween(Date date1, Date date2) {
        return getMonthsBetween(getCalendar(date1), getCalendar(date2));
    }

    /**
     * 获取两个日期相隔年份 cal2 - cal1
     * 
     * @param cal1
     * @param cal2
     * @return
     */
    public static int getYearsBetween(Calendar cal1, Calendar cal2) {
        int year2 = cal2.get(1);
        int year1 = cal1.get(1);
        return year2 - year1;
    }

    /**
     * 获取两个日期相隔年份 date2 - date1
     * 
     * @param date1
     * @param date2
     * @return
     */
    public static int getYearsBetween(Date date1, Date date2) {
        return getYearsBetween(getCalendar(date1), getCalendar(date2));
    }

    /**
     * 获取给定日期n天后（前）的日期
     * 
     * @param date
     * @param days
     * @return
     */
    public static Date addDays(Date date, int n) {
        if (date == null) {
            return null;
        }
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.DAY_OF_MONTH, n);
        return calendar.getTime();
    }

    /**
     * 获取给定日期n个月后（前）的日期
     * 
     * @param date
     * @param months
     * @return
     */
    public static Date addMonths(Date date, int n) {
        if (date == null) {
            return null;
        }
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.MONTH, n);
        return calendar.getTime();
    }

    /**
     * 获取给定日期n年后（前）的日期
     * 
     * @param date
     * @param years
     * @return
     */
    public static Date addYears(Date date, int n) {
        if (date == null) {
            return null;
        }
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.YEAR, n);
        return calendar.getTime();
    }

    /**
     * 获取给定日期n小时后（前）的日期
     * 
     * @param date
     * @param hours
     * @return
     */
    public static Date addHours(Date date, int n) {
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.HOUR_OF_DAY, n);
        return calendar.getTime();
    }

    /**
     * 获取给定日期n分钟后（前）的日期
     * 
     * @param date
     * @param minutes
     * @return
     */
    public static Date addMinutes(Date date, int n) {
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.MINUTE, n);
        return calendar.getTime();
    }

    /**
     * 获取给定日期n秒后（前）的日期
     * 
     * @param date
     * @param seconds
     * @return
     */
    public static Date addSeconds(Date date, int n) {
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.SECOND, n);
        return calendar.getTime();
    }

    /**
     * 获取上个月第一天
     * 
     * @return
     */
    public static Date getLastMonthFirstDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH, -1);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        return calendar.getTime();
    }

    /**
     * 获取上个月最后一天
     * 
     * @return
     */
    public static Date getLastMonthLastDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        calendar.add(Calendar.DATE, -1);
        return calendar.getTime();
    }
    
    /**
     * 获取当前月第一天
     * 
     * @return
     */
    public static Date getCurMonthFirstDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        return calendar.getTime();
    }

    /**
     * / 获取前月的最后一天
     * 
     * @return
     */
    public static Date getCurMonthLastDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH, 1);
        calendar.set(Calendar.DAY_OF_MONTH, 0);
        return calendar.getTime();
    }

    /**
     * 获取给定时间所在月份的第一天
     * @param date
     * @return
     */
    public static Date getSpecifyDateMonthFirstDay(Date date){
        Calendar calendar = getCalendar(date);
        calendar.add(Calendar.MONTH, 0);
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        return calendar.getTime();
    }
    public static Date getSpecifyDateMonthLastDay(Date date){
        Calendar calendar = getCalendar(date);
        calendar.add(Calendar.MONTH, 1);
        calendar.set(Calendar.DAY_OF_MONTH, 0);
        return calendar.getTime();
    }
    

    /**
     * 获取当前年份给定月份的天数
     * 
     * @return
     */
    public static int dayLenOfMonth(int m) {
        if (m == 2) {
            int year = getYear(new Date());
            if (((year % 100 == 0) && (year % 400 == 0)) || ((year % 100 != 0) && (year % 4 == 0))) {
                return 29;
            }
            return 28;
        } else if (m == 1 || m == 3 || m == 5 || m == 7 || m == 8 || m == 10 || m == 12) {
            return 31;
        } else {
            return 30;
        }
    }
    
    
    
    /**
     * 是否使用平今仓
     * @param exchangeNo    交易所编码
     * @param sysBuyDealTime    系统买入成交时间
     * @return
     */
    public static boolean isCloseToday(String exchangeNo, Date sysBuyDealTime){
        if(!"SHFE".equalsIgnoreCase(exchangeNo)){
            return false;
        }
        
        if(sysBuyDealTime == null) {
            return false;
        }
        
        //系统买入时间
        long buyTime = sysBuyDealTime.getTime();
        //当前时间
        Date now = new Date();
        //系统平仓时间
        long sysSaleTime = now.getTime();       
        //今天15点     
        Date thisDate15 = DateUtil.calcOneDay15OClock(now, 0);
        //昨天或上周五15点
        Date lastDate15 = DateUtil.calcYesterdayOrLastFriday15OClock(now);
        //明天15点
        Date nextDate15 = DateUtil.calcOneDay15OClock(now, 1);
        
        //上期所闭市时间： [01:00, 02:30, 15:00]
        if(sysSaleTime > lastDate15.getTime() && sysSaleTime <= thisDate15.getTime()) {             
            if(buyTime > lastDate15.getTime() && buyTime < thisDate15.getTime()) {
                //平今: 计算系统平仓参数
                return true;
            } else if(buyTime < lastDate15.getTime()) {
                //平仓: 计算系统平仓参数
                return false;
            }
        } 
        //上期所闭市时间： [23:00]
        else if(sysSaleTime > thisDate15.getTime() && sysSaleTime < nextDate15.getTime()) {
            //平仓
            if(buyTime < thisDate15.getTime()){
                //平仓: 计算系统平仓参数
                return false;
            } else if(buyTime > thisDate15.getTime() && buyTime < nextDate15.getTime()){
                //平今: 计算系统平仓参数
                return true;
            }
        }
        return false;
    }
    
    public static void main(String[] args) {
        
        int day = getNowDayOfYear();
        int dhour = getNowHourOfDay();
        int yhour = getNowHourOfYear();
        int wday = getNowDayOfWeek();
        logger.info("day:{}, wday:{}, dhour:{}, yhour:{}", day, wday, dhour, yhour);
        
        Date date = DateUtil.formatDate("20180102 14:25:34", "yyyyMMdd HH:mm:ss");
        logger.info("time:{}", date.getTime());
        
    }

}