Android & Java DateUtils 拿来就用 包含常用的日期和时间转换的工具

public class DateUtils2 {    // private static String defaultDatePattern = "yyyy-MM-dd ";    // private static String defaultDatePattern = "yyyyMMddHHmmssSSSZ";    private static String defaultDatePattern = "yyyyMMddHHmmss";    /**     * 获得默认的 date pattern     */    public static String getDatePattern() {        return defaultDatePattern;    }    /**     * 返回预设Format的当前日期字符串     */    public static String getToday() {        Date today = new Date();        return format(today);    }    /**     * 使用预设Format格式化Date成字符串     */    public static String format(Date date) {        return date == null ? " " : format(date, getDatePattern());    }    /**     * 使用参数Format格式化Date成字符串     */    public static String format(Date date, String pattern) {        return date == null ? " " : new SimpleDateFormat(pattern).format(date);    }    /**     * 使用预设格式将字符串转为Date     */    public static Date parse(String strDate) throws ParseException {        return StringUtils.isEmpty(strDate) ? null : parse(strDate,                getDatePattern());    }    /**     * 使用参数Format将字符串转为Date     */    public static Date parse(String strDate, String pattern) throws ParseException {        return StringUtils.isEmpty(strDate) ? null : new SimpleDateFormat(                pattern).parse(strDate);    }    /**     * 在日期上增加数个整月     */    public static Date addMonth(Date date, int n) {        Calendar cal = Calendar.getInstance();        cal.setTime(date);        cal.add(Calendar.MONTH, n);        return cal.getTime();    }    public static String getLastDayOfMonth(String year, String month) {        Calendar cal = Calendar.getInstance();        // 年        cal.set(Calendar.YEAR, Integer.parseInt(year));        // 月，因为Calendar里的月是从0开始，所以要-1        // cal.set(Calendar.MONTH, Integer.parseInt(month) - 1);        // 日，设为一号        cal.set(Calendar.DATE, 1);        // 月份加一，得到下个月的一号        cal.add(Calendar.MONTH, 1);        // 下一个月减一为本月最后一天        cal.add(Calendar.DATE, -1);        return String.valueOf(cal.get(Calendar.DAY_OF_MONTH));// 获得月末是几号    }    public static Date getDate(String year, String month, String day)            throws ParseException {        String result = year + "- " + (month.length() == 1 ? ("0 " + month) : month) + "- " + (day.length() == 1 ? ("0 " + day) : day);        return parse(result);    }    // 获取当天的开始时间    public static java.util.Date getDayBegin() {        Calendar cal = new GregorianCalendar();        cal.set(Calendar.HOUR_OF_DAY, 0);        cal.set(Calendar.MINUTE, 0);        cal.set(Calendar.SECOND, 0);        cal.set(Calendar.MILLISECOND, 0);        return cal.getTime();    }    // 获取当天的结束时间    public static java.util.Date getDayEnd() {        Calendar cal = new GregorianCalendar();        cal.set(Calendar.HOUR_OF_DAY, 23);        cal.set(Calendar.MINUTE, 59);        cal.set(Calendar.SECOND, 59);        return cal.getTime();    }    // 获取昨天的开始时间    public static Date getBeginDayOfYesterday() {        Calendar cal = new GregorianCalendar();        cal.setTime(getDayBegin());        cal.add(Calendar.DAY_OF_MONTH, -1);        return cal.getTime();    }    // 获取昨天的结束时间    public static Date getEndDayOfYesterDay() {        Calendar cal = new GregorianCalendar();        cal.setTime(getDayEnd());        cal.add(Calendar.DAY_OF_MONTH, -1);        return cal.getTime();    }    // 获取明天的开始时间    public static Date getBeginDayOfTomorrow() {        Calendar cal = new GregorianCalendar();        cal.setTime(getDayBegin());        cal.add(Calendar.DAY_OF_MONTH, 1);        return cal.getTime();    }    // 获取明天的结束时间    public static Date getEndDayOfTomorrow() {        Calendar cal = new GregorianCalendar();        cal.setTime(getDayEnd());        cal.add(Calendar.DAY_OF_MONTH, 1);        return cal.getTime();    }    // 获取本周的开始时间    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());    }    // 获取本周的结束时间    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);    }    // 获取本月的开始时间    public static Date getBeginDayOfMonth() {        Calendar calendar = Calendar.getInstance();        calendar.set(getNowYear(), getNowMonth() - 1, 1);        return getDayStartTime(calendar.getTime());    }    // 获取本月的结束时间    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());    }    // 获取本年的开始时间    public static java.util.Date getBeginDayOfYear() {        Calendar cal = Calendar.getInstance();        cal.set(Calendar.YEAR, getNowYear());        // cal.set        cal.set(Calendar.MONTH, Calendar.JANUARY);        cal.set(Calendar.DATE, 1);        return getDayStartTime(cal.getTime());    }    // 获取本年的结束时间    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());    }    // 获取某个日期的开始时间    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());    }    // 获取某个日期的结束时间    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());    }    // 获取今年是哪一年    public static Integer getNowYear() {        Date date = new Date();        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();        gc.setTime(date);        return Integer.valueOf(gc.get(1));    }    // 获取本月是哪一月    public static int getNowMonth() {        Date date = new Date();        GregorianCalendar gc = (GregorianCalendar) Calendar.getInstance();        gc.setTime(date);        return gc.get(2) + 1;    }    // 两个日期相减得到的天数    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 = new Long(diff).intValue();        return days;    }    // 两个日期相减得到的毫秒数    public static long dateDiff(Date beginDate, Date endDate) {        long date1ms = beginDate.getTime();        long date2ms = endDate.getTime();        return date2ms - date1ms;    }    // 获取两个日期中的最大日期    public static Date max(Date beginDate, Date endDate) {        if (beginDate == null) {            return endDate;        }        if (endDate == null) {            return beginDate;        }        if (beginDate.after(endDate)) {            return beginDate;        }        return endDate;    }    // 获取两个日期中的最小日期    public static Date min(Date beginDate, Date endDate) {        if (beginDate == null) {            return endDate;        }        if (endDate == null) {            return beginDate;        }        if (beginDate.after(endDate)) {            return endDate;        }        return beginDate;    }    // 返回某月该季度的第一个月    public static Date getFirstSeasonDate(Date date) {        final int[] SEASON = { 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4 };        Calendar cal = Calendar.getInstance();        cal.setTime(date);        int sean = SEASON[cal.get(Calendar.MONTH)];        cal.set(Calendar.MONTH, sean * 3 - 3);        return cal.getTime();    }    // 返回某个日期下几天的日期    public static Date getNextDay(Date date, int i) {        Calendar cal = new GregorianCalendar();        cal.setTime(date);        cal.set(Calendar.DATE, cal.get(Calendar.DATE) + i);        return cal.getTime();    }    // 返回某个日期前几天的日期    public static Date getFrontDay(Date date, int i) {        Calendar cal = new GregorianCalendar();        cal.setTime(date);        cal.set(Calendar.DATE, cal.get(Calendar.DATE) - i);        return cal.getTime();    }    // 获取某年某月到某年某月按天的切片日期集合（间隔天数的集合）    public static List getTimeList(int beginYear, int beginMonth, int endYear,            int endMonth, int k) {        List list = new ArrayList();        if (beginYear == endYear) {            for (int j = beginMonth; j <= endMonth; j++) {                list.add(getTimeList(beginYear, j, k));            }        } else {            {                for (int j = beginMonth; j < 12; j++) {                    list.add(getTimeList(beginYear, j, k));                }                for (int i = beginYear + 1; i < endYear; i++) {                    for (int j = 0; j < 12; j++) {                        list.add(getTimeList(i, j, k));                    }                }                for (int j = 0; j <= endMonth; j++) {                    list.add(getTimeList(endYear, j, k));                }            }        }        return list;    }    // 获取某年某月按天切片日期集合（某个月间隔多少天的日期集合）    public static List getTimeList(int beginYear, int beginMonth, int k) {        List list = new ArrayList();        Calendar begincal = new GregorianCalendar(beginYear, beginMonth, 1);        int max = begincal.getActualMaximum(Calendar.DATE);        for (int i = 1; i < max; i = i + k) {            list.add(begincal.getTime());            begincal.add(Calendar.DATE, k);        }        begincal = new GregorianCalendar(beginYear, beginMonth, max);        list.add(begincal.getTime());        return list;    }    /**     * 根据提供的年月日获取该月份的第一天     * @Description: (这里用一句话描述这个方法的作用)     * @Author: gyz     * @Since: 2017-1-9下午2:26:57     * @param year     * @param monthOfYear     * @return     */    public static Date getSupportBeginDayofMonth(int year, int monthOfYear) {        Calendar cal = Calendar.getInstance();        // 不加下面2行，就是取当前时间前一个月的第一天及最后一天        cal.set(Calendar.YEAR, year);        cal.set(Calendar.MONTH, monthOfYear);        cal.set(Calendar.DAY_OF_MONTH, 1);        cal.set(Calendar.HOUR_OF_DAY, 0);        cal.set(Calendar.MINUTE, 0);        cal.set(Calendar.SECOND, 0);        cal.add(Calendar.DAY_OF_MONTH, -1);        Date lastDate = cal.getTime();        cal.set(Calendar.DAY_OF_MONTH, 1);        Date firstDate = cal.getTime();        return firstDate;    }    /**     * 根据提供的年月获取该月份的最后一天     * @Description: (这里用一句话描述这个方法的作用)     * @Author: gyz     * @Since: 2017-1-9下午2:29:38     * @param year     * @param monthOfYear     * @return     */    public static Date getSupportEndDayofMonth(int year, int monthOfYear) {        Calendar cal = Calendar.getInstance();        // 不加下面2行，就是取当前时间前一个月的第一天及最后一天        cal.set(Calendar.YEAR, year);        cal.set(Calendar.MONTH, monthOfYear);        cal.set(Calendar.DAY_OF_MONTH, 1);        cal.set(Calendar.HOUR_OF_DAY, 23);        cal.set(Calendar.MINUTE, 59);        cal.set(Calendar.SECOND, 59);        cal.add(Calendar.DAY_OF_MONTH, -1);        Date lastDate = cal.getTime();        cal.set(Calendar.DAY_OF_MONTH, 1);        Date firstDate = cal.getTime();        return lastDate;    }}