Android tool-type DateUtil

Some date-related functions that may be used during development are extracted as tool classes for your reference:

/*** Date operation tool class. ** @ author shimiso */public class DateUtil {private static final String FORMAT = "yyyy-MM-dd HH: mm: ss"; public static Date str2Date (String str) {return str2Date (str, null);} public static Date str2Date (String str, String format) {if (str = null | str. length () = 0) {return null;} if (format = null | format. length () = 0) {format = FORMAT;} Date date = null; try {SimpleDateFormat sdf = new SimpleDateFormat (format); date = sdf. parse (str);} catch (Exception e) {e. printStackTrace ();} return date;} public static Calendar str2Calendar (String str) {return str2Calendar (str, null);} public static Calendar str2Calendar (String str, String format) {Date date = str2Date (str, format); if (date = null) {return null;} Calendar c = Calendar ar. getInstance (); c. setTime (date); return c;} public static String date2Str (Calendar c) {// yyyy-MM-dd HH: mm: ssreturn date2Str (c, null );} public static String date2Str (Calendar c, String format) {if (c = null) {return null;} return date2Str (c. getTime (), format);} public static String date2Str (Date d) {// yyyy-MM-dd HH: mm: ssreturn date2Str (d, null );} public static String date2Str (Date d, String format) {// yyyy-MM-dd HH: mm: ssif (d = null) {return null ;} if (format = null | format. length () = 0) {format = FORMAT;} SimpleDateFormat sdf = new SimpleDateFormat (format); String s = sdf. format (d); return s;} public static String getCurDateStr () {Calendar Ar c = Calendar ar. getInstance (); c. setTime (new Date (); return c. get (Calendar. YEAR) + "-" + (c. get (Calendar. MONTH) + 1) + "-" + c. get (Calendar. DAY_OF_MONTH) + "-" + c. get (Calendar. HOUR_OF_DAY) + ":" + c. get (Calendar. MINUTE) + ":" + c. get (Calendar. SECOND);}/*** get the String format of the current date ** @ param format * @ return */public static String getCurDateStr (String format) {Calendar c = Calendar. getInstance (); return date2Str (c, format);} // format to seconds public static String getMillon (long time) {return new SimpleDateFormat ("yyyy-MM-dd-HH-mm-ss "). format (time) ;}// the format is public static String getDay (long time) {return new SimpleDateFormat ("yyyy-MM-dd "). format (time);} // format to milliseconds public static String getSMillon (long time) {return new SimpleDateFormat ("yyyy-MM-dd-HH-mm-ss-SSS "). format (time);}/* The input format is String, such as 20120102, to add a day, the returned format is String, such as 20120103 */public static String stringDatePlus (String row) throws ParseException {String year = row. substring (0, 4); String month = row. substring (4, 6); String day = row. substring (6); String date1 = year + "-" + month + "-" + day; SimpleDateFormat sdf = new SimpleDateFormat ("yyyy-MM-dd "); date startDate = sdf. parse (date1); Calendar cd = Calendar ar. getInstance (); cd. setTime (startDate); cd. add (Calendar. DATE, 1); String dateStr = sdf. format (cd. getTime (); String year1 = dateStr. substring (0, 4); String month1 = dateStr. substring (5, 7); String day1 = dateStr. substring (8); return year1 + month1 + day1;}/* The input format is String, for example, 20120102. The return format is String, for example 20120101 */public static String stringDateDecrease (String row) throws ParseException {String year = row. substring (0, 4); String month = row. substring (4, 6); String day = row. substring (6); String date1 = year + "-" + month + "-" + day; SimpleDateFormat sdf = new SimpleDateFormat ("yyyy-MM-dd "); date startDate = sdf. parse (date1); Calendar cd = Calendar ar. getInstance (); cd. setTime (startDate); cd. add (Calendar. DATE,-1); String dateStr = sdf. format (cd. getTime (); String year1 = dateStr. substring (0, 4); String month1 = dateStr. substring (5, 7); String day1 = dateStr. substring (8); return year1 + month1 + day1;}/* The input format is String, for example, 20120101. The returned format is String, for example, 2012-01-01 */public static String stringDateChange (String date) {if (date. length () = "20120101 ". length () {String year = date. substring (0, 4); String month = date. substring (4, 6); String day = date. substring (6); return year + "-" + month + "-" + day;} else {return date ;}} /*** push the date one day backward * @ param date Format: 20120101 * @ return 20120102 */public static String tonextday (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, day + 1); Date newdate = calendar. getTime (); SimpleDateFormat format = new SimpleDateFormat ("yyyyMMdd"); String da = format. format (newdate); return da;} public static void main (String [] args) {new StringHandle (). previusweekenddaybydate ("20130109");}/*** get the start date of the previous week (Sunday) */public static String previusweekbydate (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, day); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); int dayWeek = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date if (1 = dayWeek) {cal. add (Calendar. DAY_OF_MONTH,-1);} cal. setFirstDayOfWeek (Calendar. SUNDAY); // set the first day of a week. According to China's habits, the first day of a week is Monday int s = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date. cal. add (Calendar. DATE, cal. getFirstDayOfWeek ()-s); // based on the calendar rule, subtract the current date from the day of the week to the day of the week (cal. add (Calendar. WEEK_OF_YEAR,-1); String imptimeBegin = sdf. format (cal. getTime (); // System. out. println ("date of week and Sunday:" + imptimeBegin); return imptimeBegin;}/*** get the end date of the previous week of the current date (Saturday) */public static String previousWeekEndDayByDate (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, day); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); int dayWeek = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date if (1 = dayWeek) {cal. add (Calendar. DAY_OF_MONTH,-1);} cal. setFirstDayOfWeek (Calendar. SUNDAY); // set the first day of a week. According to China's habits, the first day of a week is Monday int s = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date. cal. add (Calendar. DATE, cal. getFirstDayOfWeek () + (6-s); cal. add (Calendar. WEEK_OF_YEAR,-1); String imptimeBegin = sdf. format (cal. getTime (); // System. out. println ("Saturday date:" + imptimeBegin); return imptimeBegin;}/*** get the start date of the current week (Sunday) */public static String getCurrentWeekFirstDayByDate (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, day); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); int dayWeek = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date if (1 = dayWeek) {cal. add (Calendar. DAY_OF_MONTH,-1);} cal. setFirstDayOfWeek (Calendar. SUNDAY); // set the first day of a week. According to China's habits, the first day of a week is Monday int s = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date. cal. add (Calendar. DATE, cal. getFirstDayOfWeek ()-s); // according to the calendar rule, the difference between the current date minus the day of the week and the first day of the week String imptimeBegin = sdf. format (cal. getTime (); // System. out. println ("date of week and Sunday:" + imptimeBegin); return imptimeBegin;}/*** get the end date of the current week (Saturday) */public static String getCurrentWeekEndDayByDate (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, day); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); int dayWeek = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date if (1 = dayWeek) {cal. add (Calendar. DAY_OF_MONTH,-1);} cal. setFirstDayOfWeek (Calendar. SUNDAY); // set the first day of a week. According to China's habits, the first day of a week is Monday int s = cal. get (Calendar. DAY_OF_WEEK); // obtain the day of the week from the current date. cal. add (Calendar. DATE, cal. getFirstDayOfWeek () + (6-s); String imptimeBegin = sdf. format (cal. getTime (); return imptimeBegin;}/*** returns the first day of the previous month * @ param date20120304 * @ return 20120201 */public static String previusmonthbydate (String date) {// TODO Auto-generated method stubint year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-2, 1); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); String imptimeBegin = sdf. format (cal. getTime (); // System. out. println (imptimeBegin); return imptimeBegin;}/*** returns the first day of the next month * @ param date20120304 * @ return 20120401 */public static String nextMonthByDate (String date) {// TODO Auto-generated method stubint year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month, 1); Date newdate = calendar ar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); String imptimeBegin = sdf. format (cal. getTime (); // System. out. println (imptimeBegin); return imptimeBegin;}/*** returns the first day of the current month * @ param date20120103 * @ return 20120101 */public static String getCurrentMonthFirstDayByDate (String date) {int year = Integer. parseInt (date. substring (0, 4); int month = Integer. parseInt (date. substring (4, 6); int day = Integer. parseInt (date. substring (6); Calendar calendar = Calendar. getInstance (); calendar. set (year, month-1, 1); Date newdate = calendar. getTime (); SimpleDateFormat sdf = new SimpleDateFormat ("yyyyMMdd"); Calendar cal = Calendar ar. getInstance (); cal. setTime (newdate); String imptimeBegin = sdf. format (cal. getTime (); return imptimeBegin ;}}