DateUtils

public class DateUtil {

    private static String [] pattern = {"yyyy-MM-dd", "yyyy-MM-dd HH:mm:ss",
            "HH:mm:ss.SSSXXX","yyyy-MM-dd'T'HH:mm:ss.SSSXXX"};

    public static Date parse(String text){
        SimpleDateFormat format =  new SimpleDateFormat(pattern[0]);
        try {
            return format.parse(text);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static int getDiffDays(Date beginDate, Date endDate) {
        if (beginDate == null || endDate == null) {
            throw new IllegalArgumentException("getDiffDays param is null!");
        }
        long diff = (endDate.getTime() - beginDate.getTime())
                / (1000 * 60 * 60 * 24);
        int days = Long.valueOf(diff).intValue();
        return days;
    }
    //獲取年度開始時間
    public static Date getStartDateOfYear(Integer year){
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, Calendar.JANUARY);
        cal.set(Calendar.DATE, 1);
       return getDayStartTime(cal.getTime());
    }
    //獲取年度結束時間
    public static Date getEndDateOfYear(Integer year){
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, Calendar.DECEMBER);
        cal.set(Calendar.DATE, 31);
       return getDayStartTime(cal.getTime());
    }
    //獲取某月開始時間
    public static Date getStartMonth(Integer month){
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), month - 1, 1);
        return getDayStartTime(calendar.getTime());
    }
    //獲取某月結束時間
    public static Date getEndMonth(Integer month) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), month - 1, 1);
        int day = calendar.getActualMaximum(5);
        calendar.set(getNowYear(), month - 1, day);
        return getDayEndTime(calendar.getTime());

    }
    // 獲取本年的開始時間
    public static Date getBeginDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, getNowYear());
        cal.set(Calendar.MONTH, Calendar.JANUARY);
        cal.set(Calendar.DATE, 1);
        return getDayStartTime(cal.getTime());
    }

    // 獲取本年的結束時間
    public static java.util.Date getEndDayOfYear() {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, getNowYear());
        cal.set(Calendar.MONTH, Calendar.DECEMBER);
        cal.set(Calendar.DATE, 31);
        return getDayEndTime(cal.getTime());
    }

    // 獲取本週的開始時間
    public static Date getBeginDayOfWeek() {
        Date date = new Date();
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
        if (dayofweek == 1) {
            dayofweek += 7;
        }
        cal.add(Calendar.DATE, 2 - dayofweek);
        return getDayStartTime(cal.getTime());
    }

    // 獲取本週的結束時間
    public static Date getEndDayOfWeek() {
        Calendar cal = Calendar.getInstance();
        cal.setTime(getBeginDayOfWeek());
        cal.add(Calendar.DAY_OF_WEEK, 6);
        Date weekEndSta = cal.getTime();
        return getDayEndTime(weekEndSta);
    }

    // 獲取某個日期的開始時間
    public static Timestamp getDayStartTime(Date d) {
        Calendar calendar = Calendar.getInstance();
        if (null != d)
            calendar.setTime(d);
        calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        return new Timestamp(calendar.getTimeInMillis());
    }

    // 獲取某個日期的結束時間
    public static Timestamp getDayEndTime(Date d) {
        Calendar calendar = Calendar.getInstance();
        if (null != d)
            calendar.setTime(d);
        calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 23, 59, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        return new Timestamp(calendar.getTimeInMillis());
    }

    // 獲取本月的開始時間
    public static Date getBeginDayOfMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 1, 1);
        return getDayStartTime(calendar.getTime());
    }

    // 獲取本月的結束時間
    public static Date getEndDayOfMonth() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(getNowYear(), getNowMonth() - 1, 1);
        int day = calendar.getActualMaximum(5);
        calendar.set(getNowYear(), getNowMonth() - 1, day);
        return getDayEndTime(calendar.getTime());

    }
    // 獲取今年是哪一年
    public static Integer getNowYear() {
        Date date = new Date();
        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
        gc.setTime(date);
        return Integer.valueOf(gc.get(1));
    }

    // 獲取本月是哪一月
    public static int getNowMonth() {
        Date date = new Date();
        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();
        gc.setTime(date);
        return gc.get(2) + 1;

    }
    //獲取當天整點時間戳
    public static Long getTodayZeroPointTimestamps(){
        Long currentTimestamps=System.currentTimeMillis();
        Long oneDayTimestamps= Long.valueOf(60*60*24*1000);
        return currentTimestamps-(currentTimestamps+60*60*8*1000)%oneDayTimestamps;
    }

}