• 使用日期工具类:DateUtil


    利用java开发,避免不了String、Date转换,前一天、后一天等问题。给出一个工具类,仅供学习交流。

    java8 线程安全写法

        public static String getLocalDateStr(Date date, String formatter) {
            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern(formatter);
            Instant instant = date.toInstant();
            ZoneId zoneId = ZoneId.systemDefault();
            LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, zoneId);
            String dateStr = dateTimeFormatter.format(localDateTime);
            return dateStr;
        }
    
        public static void main(String[] args) {
            System.out.println(getLocalDateStr(new Date(), webFormat));
        }
    

      

    import java.text.DateFormat;
    import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    import java.util.GregorianCalendar;
    import java.util.Locale;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    
    
    public class DateUtil {
    
        public final static long   ONE_DAY_SECONDS       = 86400;
        public final static String shortFormat           = "yyyyMMdd";
        public final static String longFormat            = "yyyyMMddHHmmss";
        public final static String concurrentFormat      = "yyyyMMddHHmmssSSS";
        public final static String shortConcurrentFormat = "yyMMddHHmmssSSS";
        public final static String webFormat             = "yyyy-MM-dd";
        public final static String webMonthFormat        = "yyyy-MM";
        public final static String timeFormat            = "HH:mm:ss";
        public final static String monthFormat           = "yyyyMM";
        public final static String chineseDtFormat       = "yyyy年MM月dd日";
        public final static String chineseYMFormat       = "yyyy年MM月";
        public final static String newFormat             = "yyyy-MM-dd HH:mm:ss";
        public final static String noSecondFormat        = "yyyy-MM-dd HH:mm";
        public final static String MdFormat = "MM-dd";
        public final static long   ONE_DAY_MILL_SECONDS  = 86400000;

    public static DateFormat getNewDateFormat(String pattern) { DateFormat df = new SimpleDateFormat(pattern); df.setLenient(false); return df; } public static String format(Date date, String format) { if (date == null) { return null; } return new SimpleDateFormat(format).format(date); } public static String format(String dateStr, String oldFormat, String newFormat) { if (dateStr == null) { return null; } String result = null; DateFormat oldDateFormat = new SimpleDateFormat(oldFormat); DateFormat newDateFormat = new SimpleDateFormat(newFormat); try { Date date = oldDateFormat.parse(dateStr); result = newDateFormat.format(date); } catch (ParseException e) { e.printStackTrace(); } return result; } public static Date parseDateNoTime(String sDate) { DateFormat dateFormat = new SimpleDateFormat(shortFormat); Date date = null; if ((sDate == null) || (sDate.length() < shortFormat.length())) { return null; } if (!StringUtil.isNumeric(sDate)) { return null; } try { date = dateFormat.parse(sDate); } catch (ParseException e) { e.printStackTrace(); } return date; } public static Date parseDateNoTime(String sDate, String format) throws ParseException { if (StringUtil.isBlank(format)) { throw new ParseException("Null format. ", 0); } DateFormat dateFormat = new SimpleDateFormat(format); if ((sDate == null) || (sDate.length() < format.length())) { throw new ParseException("length too little", 0); } return dateFormat.parse(sDate); } public static Date parseDateNoTimeWithDelimit(String sDate, String delimit) throws ParseException { sDate = sDate.replaceAll(delimit, ""); DateFormat dateFormat = new SimpleDateFormat(shortFormat); if ((sDate == null) || (sDate.length() != shortFormat.length())) { throw new ParseException("length not match", 0); } return dateFormat.parse(sDate); } public static Date parseDateLongFormat(String sDate) { DateFormat dateFormat = new SimpleDateFormat(longFormat); Date d = null; if ((sDate != null) && (sDate.length() == longFormat.length())) { try { d = dateFormat.parse(sDate); } catch (ParseException ex) { return null; } } return d; } public static Date parseDateNewFormat(String sDate) { DateFormat dateFormat = new SimpleDateFormat(newFormat); Date d = null; dateFormat.setLenient(false); if ((sDate != null) && (sDate.length() == newFormat.length())) { try { d = dateFormat.parse(sDate); } catch (ParseException ex) { return null; } } return d; } public static Date parseDateNoSecondFormat(String sDate) { DateFormat dateFormat = new SimpleDateFormat(noSecondFormat); Date d = null; dateFormat.setLenient(false); if ((sDate != null) && (sDate.length() == noSecondFormat.length())) { try { d = dateFormat.parse(sDate); } catch (ParseException ex) { return null; } } return d; } public static Date parseDateWebFormat(String sDate) { DateFormat dateFormat = new SimpleDateFormat(webFormat); Date d = null; dateFormat.setLenient(false); if ((sDate != null) && (sDate.length() == webFormat.length())) { try { d = dateFormat.parse(sDate); } catch (ParseException ex) { return null; } } return d; } public static Date parseDateWebMonthFormat(String sDate) { DateFormat dateFormat = new SimpleDateFormat(webMonthFormat); Date d = null; dateFormat.setLenient(false); if ((sDate != null) && (sDate.length() == webMonthFormat.length())) { try { d = dateFormat.parse(sDate); } catch (ParseException ex) { return null; } } return d; } /** * 计算当前时间几小时之后的时间 * * @param date * @param hours * * @return */ public static Date addHours(Date date, long hours) { return addMinutes(date, hours * 60); } /** * 计算当前时间几分钟之后的时间 * * @param date * @param minutes * * @return */ public static Date addMinutes(Date date, long minutes) { return addSeconds(date, minutes * 60); } /** * @param date1 * @param secs * * @return */ public static Date addSeconds(Date date1, long secs) { return new Date(date1.getTime() + (secs * 1000)); } /** * 判断输入的字符串是否为合法的小时 * * @param hourStr * * @return true/false */ public static boolean isValidHour(String hourStr) { if (!StringUtil.isEmpty(hourStr) && StringUtil.isNumeric(hourStr)) { int hour = new Integer(hourStr).intValue(); if ((hour >= 0) && (hour <= 23)) { return true; } } return false; } /** * 判断输入的字符串是否为合法的分或秒 * * @param minuteStr * * @return true/false */ public static boolean isValidMinuteOrSecond(String str) { if (!StringUtil.isEmpty(str) && StringUtil.isNumeric(str)) { int hour = new Integer(str).intValue(); if ((hour >= 0) && (hour <= 59)) { return true; } } return false; } /** * 取得新的日期 * * @param date1 * 日期 * @param days * 天数 * * @return 新的日期 */ public static Date addDays(Date date1, long days) { Calendar cal = Calendar.getInstance(); cal.setTime(date1); cal.add(Calendar.DATE, (int) days); return cal.getTime(); } public static String getTomorrowDateString(String sDate) throws ParseException { Date aDate = parseDateNoTime(sDate); aDate = addSeconds(aDate, ONE_DAY_SECONDS); return getDateString(aDate); } public static String getTomorrowDateNewFMTString(String sDate) throws ParseException { Date aDate = parseDateWebFormat(sDate); aDate = addDays(aDate, 1); return getWebDateString(aDate); } public static String getTomorrowDateNewFormatString(String sDate) throws ParseException { Date aDate = parseDateNewFormat(sDate); aDate = addDays(aDate, 1); return getWebDateString(aDate); } public static String getLongDateString(Date date) { DateFormat dateFormat = new SimpleDateFormat(longFormat); return getDateString(date, dateFormat); } public static String getNewFormatDateString(Date date) { DateFormat dateFormat = new SimpleDateFormat(newFormat); return getDateString(date, dateFormat); } public static String getWebFormatDateString(Date date) { DateFormat dateFormat = new SimpleDateFormat(webFormat); return getDateString(date, dateFormat); } public static String getConcurrentFormatDateString(Date date) { DateFormat dateFormat = new SimpleDateFormat(concurrentFormat); return getDateString(date, dateFormat); } public static String getDateString(Date date, DateFormat dateFormat) { if (date == null || dateFormat == null) { return null; } return dateFormat.format(date); } public static String getYesterDayDateString(String sDate) throws ParseException { Date aDate = parseDateNoTime(sDate); aDate = addSeconds(aDate, -ONE_DAY_SECONDS); return getDateString(aDate); } /** * @return 当天的时间格式化为"yyyyMMdd" */ public static String getDateString(Date date) { DateFormat df = getNewDateFormat(shortFormat); return df.format(date); } public static String getWebDateString(Date date) { DateFormat dateFormat = getNewDateFormat(webFormat); return getDateString(date, dateFormat); } /** * 取得“X年X月X日”的日期格式 * * @param date * * @return */ public static String getChineseDateString(Date date) { DateFormat dateFormat = getNewDateFormat(chineseDtFormat); return getDateString(date, dateFormat); } public static String getTodayString() { DateFormat dateFormat = getNewDateFormat(shortFormat); return getDateString(new Date(), dateFormat); } public static String getTomorrowString() { DateFormat dateFormat = getNewDateFormat(shortFormat); return getDateString(DateUtil.addDays(new Date(), 1), dateFormat); } public static String getTimeString(Date date) { DateFormat dateFormat = getNewDateFormat(timeFormat); return getDateString(date, dateFormat); } public static String getBeforeDayString(int days) { Date date = new Date(System.currentTimeMillis() - (ONE_DAY_MILL_SECONDS * days)); DateFormat dateFormat = getNewDateFormat(shortFormat); return getDateString(date, dateFormat); } /** * 取得两个日期间隔毫秒数(日期1-日期2) * * @param one * 日期1 * @param two * 日期2 * * @return 间隔秒数 */ public static long getDiffMillis(Date one, Date two) { Calendar sysDate = new GregorianCalendar(); sysDate.setTime(one); Calendar failDate = new GregorianCalendar(); failDate.setTime(two); return (sysDate.getTimeInMillis() - failDate.getTimeInMillis()); } /** * 取得两个日期间隔秒数(日期1-日期2) * * @param one * 日期1 * @param two * 日期2 * * @return 间隔秒数 */ public static long getDiffSeconds(Date one, Date two) { Calendar sysDate = new GregorianCalendar(); sysDate.setTime(one); Calendar failDate = new GregorianCalendar(); failDate.setTime(two); return (sysDate.getTimeInMillis() - failDate.getTimeInMillis()) / 1000; } /** * 取得两个日期间隔分钟数(日期1-日期2) * * @param one * 日期1 * @param two * 日期2 * * @return 间隔秒数 */ public static long getDiffMinutes(Date one, Date two) { Calendar sysDate = new GregorianCalendar(); sysDate.setTime(one); Calendar failDate = new GregorianCalendar(); failDate.setTime(two); return (sysDate.getTimeInMillis() - failDate.getTimeInMillis()) / (60 * 1000); } /** * 取得两个日期的间隔天数 * * @param one * @param two * * @return 间隔天数 */ public static long getDiffDays(Date one, Date two) { Calendar sysDate = new GregorianCalendar(); sysDate.setTime(one); Calendar failDate = new GregorianCalendar(); failDate.setTime(two); return (sysDate.getTimeInMillis() - failDate.getTimeInMillis()) / (24 * 60 * 60 * 1000); } /** * 取得两个日期相差的自然日 * * @param date1 * @param date2 * @return */ public static long getDiffNaturalDays(Date date1, Date date2) { Long diffDays = 0L; DateFormat dateFormat = new SimpleDateFormat(webFormat); //去掉时分秒 String dateStr1 = dateFormat.format(date1); String dateStr2 = dateFormat.format(date2); try { diffDays = (dateFormat.parse(dateStr1).getTime() - dateFormat.parse(dateStr2).getTime()) / (24 * 60 * 60 * 1000); } catch (ParseException e) { e.printStackTrace(); } return Math.abs(diffDays); } /** * 取得两个日期相差的自然日 * * @param date1 * @param date2 * @return */ public static long getDiffNaturalDayNotAbs(Date date1, Date date2) { Long diffDays = 0L; DateFormat dateFormat = new SimpleDateFormat(webFormat); //去掉时分秒 String dateStr1 = dateFormat.format(date1); String dateStr2 = dateFormat.format(date2); try { diffDays = (dateFormat.parse(dateStr1).getTime() - dateFormat.parse(dateStr2).getTime()) / (24 * 60 * 60 * 1000); } catch (ParseException e) { e.printStackTrace(); } return diffDays; } public static String getBeforeDayString(String dateString, int days) { Date date; DateFormat df = getNewDateFormat(shortFormat); try { date = df.parse(dateString); } catch (ParseException e) { date = new Date(); } date = new Date(date.getTime() - (ONE_DAY_MILL_SECONDS * days)); return df.format(date); } public static boolean isValidShortDateFormat(String strDate) { if (strDate.length() != shortFormat.length()) { return false; } try { Integer.parseInt(strDate); // ---- 避免日期中输入非数字 ---- } catch (Exception NumberFormatException) { return false; } DateFormat df = getNewDateFormat(shortFormat); try { df.parse(strDate); } catch (ParseException e) { return false; } return true; } public static boolean isValidShortDateFormat(String strDate, String delimiter) { String temp = strDate.replaceAll(delimiter, ""); return isValidShortDateFormat(temp); } /** * 判断表示时间的字符是否为符合yyyyMMddHHmmss格式 * * @param strDate * @return */ public static boolean isValidLongDateFormat(String strDate) { if (strDate.length() != longFormat.length()) { return false; } try { Long.parseLong(strDate); // ---- 避免日期中输入非数字 ---- } catch (Exception NumberFormatException) { return false; } DateFormat df = getNewDateFormat(longFormat); try { df.parse(strDate); } catch (ParseException e) { return false; } return true; } /** * 判断表示时间的字符是否为符合yyyyMMddHHmmss格式 * * @param strDate * @param delimiter * @return */ public static boolean isValidLongDateFormat(String strDate, String delimiter) { String temp = strDate.replaceAll(delimiter, ""); return isValidLongDateFormat(temp); } public static String getShortDateString(String strDate) { return getShortDateString(strDate, "-|/"); } public static String getShortDateString(String strDate, String delimiter) { if (StringUtil.isBlank(strDate)) { return null; } String temp = strDate.replaceAll(delimiter, ""); if (isValidShortDateFormat(temp)) { return temp; } return null; } public static String getShortFirstDayOfMonth() { Calendar cal = Calendar.getInstance(); Date dt = new Date(); cal.setTime(dt); cal.set(Calendar.DAY_OF_MONTH, 1); DateFormat df = getNewDateFormat(shortFormat); return df.format(cal.getTime()); } public static String getWebTodayString() { DateFormat df = getNewDateFormat(webFormat); return df.format(new Date()); } /** * 获取当月首日 * * @return */ public static String getWebFirstDayOfMonth() { Calendar cal = Calendar.getInstance(); Date dt = new Date(); cal.setTime(dt); cal.set(Calendar.DAY_OF_MONTH, 1); DateFormat df = getNewDateFormat(webFormat); return df.format(cal.getTime()); } /** * 获取当月的总天数 * * @return */ public static int getDaysOfMonth() { Calendar cal = Calendar.getInstance(Locale.CHINA); int days = cal.getActualMaximum(Calendar.DATE); return days; } public static String convert(String dateString, DateFormat formatIn, DateFormat formatOut) { try { Date date = formatIn.parse(dateString); return formatOut.format(date); } catch (ParseException e) { return ""; } } public static String convert2WebFormat(String dateString) { DateFormat df1 = getNewDateFormat(shortFormat); DateFormat df2 = getNewDateFormat(webFormat); return convert(dateString, df1, df2); } public static String convert2ChineseDtFormat(String dateString) { DateFormat df1 = getNewDateFormat(shortFormat); DateFormat df2 = getNewDateFormat(chineseDtFormat); return convert(dateString, df1, df2); } public static String convertFromWebFormat(String dateString) { DateFormat df1 = getNewDateFormat(shortFormat); DateFormat df2 = getNewDateFormat(webFormat); return convert(dateString, df2, df1); } public static boolean webDateNotLessThan(String date1, String date2) { DateFormat df = getNewDateFormat(webFormat); return dateNotLessThan(date1, date2, df); } /** * @param date1 * @param date2 * @param dateWebFormat2 * * @return */ public static boolean dateNotLessThan(String date1, String date2, DateFormat format) { try { Date d1 = format.parse(date1); Date d2 = format.parse(date2); if (d1.before(d2)) { return false; } else { return true; } } catch (ParseException e) { return false; } } public static String getEmailDate(Date today) { String todayStr; SimpleDateFormat sdf = new SimpleDateFormat("yyyy年MM月dd日HH:mm:ss"); todayStr = sdf.format(today); return todayStr; } public static String getSmsDate(Date today) { String todayStr; SimpleDateFormat sdf = new SimpleDateFormat("MM月dd日HH:mm"); todayStr = sdf.format(today); return todayStr; } public static String formatMonth(Date date) { if (date == null) { return null; } return new SimpleDateFormat(monthFormat).format(date); } /** * 获取系统日期的前一天日期,返回Date * * @return */ public static Date getBeforeDate() { Date date = new Date(); return new Date(date.getTime() - (ONE_DAY_MILL_SECONDS)); } /** * 获得指定时间当天起点时间 * * @param date * @return */ public static Date getDayBegin(Date date) { DateFormat df = new SimpleDateFormat("yyyyMMdd"); df.setLenient(false); String dateString = df.format(date); try { return df.parse(dateString); } catch (ParseException e) { return date; } } /** * 根据Date对象返回今天是星期几 * * @param date * @return 1:星期日 2:星期一 3:星期二 4:星期三 5:星期四 6:星期五 7:星期六 */ public static int getWeekDayFromDateEntity(Date date) { Calendar calendar = Calendar.getInstance();// 获得一个日历 calendar.setTime(date); int number = calendar.get(Calendar.DAY_OF_WEEK);// 星期表示1-7,是从星期日开始, return number; } /** * 判断参date上min分钟后,是否小于当前时间 * * @param date * @param min * @return */ public static boolean dateLessThanNowAddMin(Date date, long min) { return addMinutes(date, min).before(new Date()); } public static boolean isBeforeNow(Date date) { if (date == null) return false; return date.compareTo(new Date()) < 0; } private static SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); // 获得当前月--开始日期 public static Date getMinMonthDate(String date) { Calendar calendar = Calendar.getInstance(); try { calendar.setTime(dateFormat.parse(date)); calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMinimum(Calendar.DAY_OF_MONTH)); return calendar.getTime(); } catch (ParseException e) { return null; } } // 获得当前月--结束日期 public static Date getMaxMonthDate(String date) { Calendar calendar = Calendar.getInstance(); try { calendar.setTime(dateFormat.parse(date)); calendar.set(Calendar.DAY_OF_MONTH, calendar.getActualMaximum(Calendar.DAY_OF_MONTH)); return calendar.getTime(); } catch (ParseException e) { return null; } } public static Date parseNoSecondFormat(String sDate) throws ParseException { DateFormat dateFormat = new SimpleDateFormat(noSecondFormat); if ((sDate == null) || (sDate.length() < noSecondFormat.length())) { throw new ParseException("length too little", 0); } if (!StringUtil.isNumeric(sDate)) { throw new ParseException("not all digit", 0); } return dateFormat.parse(sDate); } /* * * date日期转变成 制定格式字符串 * */ public static String convertDate2String(Date date, String time_pattern) { SimpleDateFormat sf = new SimpleDateFormat(time_pattern); return sf.format(date); } /** * 根据Date对象返回天 * * * @param date */ public static int getDayFromDateEntity(Date date) { Calendar calendar = Calendar.getInstance();// 获得一个日历 calendar.setTime(date); int number = calendar.get(Calendar.DATE);// 星期表示1-7,是从星期日开始, return number; } public static int compare_date(String DATE1, String DATE2) { DateFormat df = new SimpleDateFormat("yyyy-MM"); try { Date dt1 = df.parse(DATE1); Date dt2 = df.parse(DATE2); if (dt1.getTime() > dt2.getTime()) { //System.out.println("dt1 在dt2前"); return 1; } else if (dt1.getTime() < dt2.getTime()) { //System.out.println("dt1在dt2后"); return -1; } else { return 0; } } catch (Exception exception) { exception.printStackTrace(); } return 0; } public static String getCurMonth() { return format(new Date(), webMonthFormat); } public static String getChineseYMString(String date) { SimpleDateFormat sdf = new SimpleDateFormat(chineseYMFormat); try { Date datea = sdf.parse(date); DateFormat dateFormat = getNewDateFormat(chineseYMFormat); return getDateString(datea, dateFormat); } catch (ParseException ex) { Logger.getLogger(DateUtil.class.getName()).log(Level.SEVERE, null, ex); return date; } } public static Date getPreMonthDate(String date) { SimpleDateFormat sdf = new SimpleDateFormat(webMonthFormat); try { Date datea = sdf.parse(date); Calendar cal = Calendar.getInstance(); cal.setTime(datea); cal.add(Calendar.MONTH, -1); return cal.getTime(); } catch (ParseException ex) { Logger.getLogger(DateUtil.class.getName()).log(Level.SEVERE, null, ex); return new Date(); } } public static Date getNextMonthDate(String date) { SimpleDateFormat sdf = new SimpleDateFormat(webMonthFormat); try { Date datea = sdf.parse(date); Calendar cal = Calendar.getInstance(); cal.setTime(datea); cal.add(Calendar.MONTH, 1); return cal.getTime(); } catch (ParseException ex) { Logger.getLogger(DateUtil.class.getName()).log(Level.SEVERE, null, ex); return new Date(); } } /** * 获取指定日期的当月的第一天 * * @param date * @return */ public static String getAssignedDateFirstDayOfMonth(Date date) { Calendar cal = Calendar.getInstance(); cal.setTime(date); cal.set(Calendar.DAY_OF_MONTH, cal.getActualMinimum(Calendar.DAY_OF_MONTH)); DateFormat df = getNewDateFormat(webFormat); return df.format(cal.getTime()); } /** * 获取指定日期的当月的最后一天 * * @param date * @return */ public static String getAssignedDateLastDayOfMonth(Date date) { Calendar cal = Calendar.getInstance(); cal.setTime(date); cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH)); DateFormat df = getNewDateFormat(webFormat); return df.format(cal.getTime()); } public static Date getNextDate(Date date) { try { Calendar calendar = Calendar.getInstance(); calendar.setTime(date); calendar.add(Calendar.DAY_OF_MONTH, 1); Date date1 = new Date(calendar.getTimeInMillis()); return date1; } catch (Exception ex) { Logger.getLogger(DateUtil.class.getName()).log(Level.SEVERE, null, ex); return date; } } /** * 根据年 月 获取对应的月份 天数 * */ public static int getDaysByYearMonth(int year, int month) { Calendar a = Calendar.getInstance(); a.set(Calendar.YEAR, year); a.set(Calendar.MONTH, month - 1); a.set(Calendar.DATE, 1); a.roll(Calendar.DATE, -1); int maxDate = a.get(Calendar.DATE); return maxDate; } }
    梦想还是要有的,万一实现了呢!
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  • 原文地址:https://www.cnblogs.com/jianfeijiang/p/6148340.html
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