Java Date Manipulation Tool class

Original: Java Date manipulation Tool class

Source code: Http://www.zuidaima.com/share/1550463481580544.htm

Here are some of the commonly used date processing methods, written is very comprehensive, I hope someone can write their own good date processing code updated into the inside

Package Com.zuidaima.date.util;import Java.text.parseposition;import Java.text.simpledateformat;import Java.util.calendar;import Java.util.date;import Java.util.regex.pattern;import Org.apache.commons.logging.Log; Import org.apache.commons.logging.logfactory;/*** @author Www.zuidaima.com**/public class Dateutil {protected static Log logger = Logfactory.getlog (dateutil.class);//format: Year-month-day hour: minutes: Second public static final String Format_one = "Yyyy-mm-dd    HH:mm:ss ";    Format: Year-month-day hour: minutes public static final String format_two = "Yyyy-mm-dd hh:mm";    Format: Month Day hour minute second public static final String Format_three = "YYYYMMDD-HHMMSS";    Format: Year-month-day public static final String Long_date_format = "YYYY-MM-DD";    Format: Month-day public static final String Short_date_format = "MM-DD";    Format: Hours: minutes: Seconds public static final String Long_time_format = "HH:mm:ss";    Format: Year-month public static final String Montg_date_format = "yyyy-mm";    The plus and minus public static final int sub_year = calendar.year; //Month plus minus public static final int sub_month = Calendar.month;    Days of addition and subtraction public static final int sub_day = calendar.date;    Hours of addition and subtraction public static final int sub_hour = Calendar.hour;    Addition and subtraction of minutes public static final int sub_minute = Calendar.minute;    The addition and subtraction of the second public static final int sub_second = Calendar.second;    Static final String daynames[] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}; @SuppressWarnings ("unused") private static final SimpleDateFormat TimeFormat = new SimpleDateFormat ("Yyyy-m    M-dd HH:mm:ss "); Public Dateutil () {}/** * Converts a string that conforms to a date format to a date type */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; /** * Converts a string that matches a date format to a date type * @author www.zuidaima.com */public static java.util.Date stringtodate (string datestr, string format, Pa        Rseposition 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; }/** * Convert date to String */public static string datetostring (java.util.Date date, string format) {string R        Esult = "";        SimpleDateFormat formater = new SimpleDateFormat (format);        try {result = Formater.format (date);        } catch (Exception e) {//Log.error (e);    } return result; /** * Gets the specified format of the current time */public static string Getcurrdate (string format) {return datetostring (new date    (), format); public static string datesub (int datekind, string datestr, int amount) {Date date = StringtodatE (Datestr, format_one);        Calendar calendar = Calendar.getinstance ();        Calendar.settime (date);        Calendar.add (Datekind, amount);    Return datetostring (Calendar.gettime (), format_one);        }/** * Two date subtraction * @return Subtract the number of seconds */public static long Timesub (string firsttime, String sectime) {        Long first = Stringtodate (Firsttime, Format_one). GetTime ();        Long second = Stringtodate (Sectime, Format_one). GetTime ();    Return (Second-first)/1000;        }/** * Gets the number of days in a month */public static int Getdaysofmonth (string year, string month) {int day = 0;  if (Month.equals ("1") | | | month.equals ("3") | | month.equals ("5") | | month.equals ("7") | | month.equals ("8") || Month.equals ("10") | |        Month.equals ("n")) {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)% + = = 0) {days = 29;            } else {days = 28;    }} return days; /** * Gets the number of days of the month in a year */public static int getdaysofmonth (int year, int month) {Calendar calendar = Cale        Ndar.getinstance ();        Calendar.set (year, month-1, 1);    Return Calendar.getactualmaximum (Calendar.day_of_month);        }/** * Gets the current date */public static int gettoday () {Calendar calendar = calendar.getinstance ();    Return Calendar.get (calendar.date);        }/** * Gets the current month */public static int gettomonth () {Calendar calendar = calendar.getinstance ();    Return Calendar.get (Calendar.month) + 1;        }/** * Gets the current year */public static int gettoyear () {Calendar calendar = calendar.getinstance ();    Return Calendar.get (calendar.year); }    /**     * Day of Return date */public static int GetDay (date date) {Calendar calendar = calendar.getinstance ();        Calendar.settime (date);    Return Calendar.get (calendar.date);        }/** * Returns the year of the date */public static int getYear (date date) {Calendar calendar = calendar.getinstance ();        Calendar.settime (date);    Return Calendar.get (calendar.year); }/** * Returns the month of the date, 1-12 */public static int getMonth (date date) {Calendar calendar = Calendar.getinsta        NCE ();        Calendar.settime (date);    Return Calendar.get (Calendar.month) + 1;        }/** * Calculates the number of days between two dates, if Date2 > date1 returns positive numbers, otherwise returns negative */public static long Daydiff (date date1, date date2) {    Return (Date2.gettime ()-date1.gettime ())/86400000; }/** * Compares the year difference of two dates */public static int Yeardiff (string before, string after) {Date Beforeday = Strin        Gtodate (before, Long_date_format); Date Afterday = Stringtodate (After, long_date_format);    Return GetYear (Afterday)-getYear (Beforeday);        /** * Compare the difference between the specified date and the current date */public static int Yeardiffcurr (String after) {Date beforeday = new Date ();        Date Afterday = Stringtodate (after, Long_date_format);    Return GetYear (Beforeday)-getYear (Afterday); /** * Compare the difference between the specified date and the current date */public static long Daydiffcurr (String before) {Date currdate = Dateutil        . Stringtodate (Currday (), Long_date_format);        Date beforedate = Stringtodate (before, Long_date_format);    Return (Currdate.gettime ()-beforedate.gettime ())/86400000; }/** * Gets the current date * */public static String Currday () {return datetostring (new Date (), Long_date_format    ); }/** * Gets the first week of the month */public static int getfirstweekdayofmonth (int year, int month) {Calendar c =        Calendar.getinstance (); C.setfirstdayofweek (Calendar.saturday);        Sunday for the first day C.set (year, month-1, 1); Return C.get (CalendaR.day_of_week); }/** * Gets the last week of the month */public static int getlastweekdayofmonth (int year, int month) {Calendar c = Cale        Ndar.getinstance (); C.setfirstdayofweek (Calendar.saturday);        Sunday for the first day C.set (year, Month-1, Getdaysofmonth (year, month));    Return C.get (Calendar.day_of_week); }/** * Gets the current date string, format "YYYY-MM-DD HH:mm:ss" * * @return */public static string Getnow () {Cal        Endar today = Calendar.getinstance ();    Return datetostring (Today.gettime (), format_one); }/** * Convert java.util.date type to Java.sql.date * @param date * @return */public static Java.sql.Timesta MP GetDate (Java.util.Date Date) {//java.sql.date sqldate = new Java.sql.Date (); Java.sql.Timestamp Timestamp = new JAVA.SQ    L.timestamp (Date.gettime ()); return Timestamp;} /** * Determines whether a date is valid, including a leap year condition * * @param date * YYYY-MM-DD * @return * */public static Boolea n 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 (); }}

Java Date Manipulation Tool class