Java date operation, date, Calendar operation

Java development can not avoid the date-related operations, here summarizes some common methods ~

Directly on the code:

Package jse;import java.io.unsupportedencodingexception;import java.text.parseexception;import  java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import  java.util.locale;/** *  Common date Operations  *  *  @author  puck * createdate  2015-07-30 22:54:38 */public class testdate{public static void main ( String[] args)  throws ParseException, UnsupportedEncodingException{Calendar cal  = calendar.getinstance ();//cal.add (calendar.day_of_month, -48); System.out.println (Datetostring (CAL));} /** *  date formatting  *  @param  date *  @return  */public static string  datetostring (date date) {//simpledateformat format = new simpledateformat (" y mm month dd Day  e hh mm min ss sec ",  locale.china);//simpledateformat format = new  SimpleDateFormat ("Y year M month D-Day  e&nbsP H M min s second ",  locale.china); Simpledateformat sdf = new simpledateformat ("Yyyy-mm-dd hh:mm:ss",  Locale.CHINA) ;  // examplereturn sdf.format (date);} /** *  date formatting  *  @param  date *  @return  */public static string  datetostring (calendar cal) {return datetostring (Cal.gettime ());} /** * datestring  Transfer  Calendar *  *  @param  Date *             format:2015-06-16 date *  @return  Calendar *  @throws  ParseException */public static Calendar  Datestringtocalendar (STRING DATESTR)  throws ParseException{//Calendar cal =  Calendar.getinstance ();//cal.clear ();//cal.set (Integer.parseint (date.substring)) 0, 4 Integer.parseint (date.substring (5, 7))  - 1,//integer.parseint (date.substring (8, 10)));//return cal; Simpledateformat sdf = new simpledateformat ("Yyyy-mm-dd hh:mm:ss");D ate date  = sdf.parse (DATESTR); Calendar cal = calendar.getinstance (); Cal.settime (date); return cal;} /** * datestring  Transfer  Date *  *  @param  Date *             format:yyyy-mm-dd hh:mm:ss date * @ return calendar *  @throws  ParseException */public static Date  Datestringtodate (string date)  throws parseexception{simpledateformat sdf = new  simpledateformat ("Yyyy-mm-dd hh:mm:ss"); Return sdf.parse (date);} /** * date convert to calendar *  *  @param  date *  @return  */public static calendar datetocalendar (date date) {calendar c1 =  calendar.getinstance (); C1.settime (date); return c1;} /** * calendar convert to date *  @param  cal *  @return  * /public static date calendartodate (calendar cal) {return cal.gettime ();} /** *  Calculation Two date difference month date  *  *  @param  Date *             c1 *  @param  Date *             c2 *  @return  int[]{year, month, day} * /public int[] calculatedifferday (DATE D1, DATE D2) {calendar c1 =  Calendar.getinstance (); C1.settime (D1); Calendar c2 = calendar.getinstance (); C1.settime (D2); Return calculatedifferday (C1, C2) ;} /** *  Calculation Two date difference month date  *  *  @param  Calendar *             c1 *  @param   calendar *            c2 *  @return  int[]{year, month, day} */public int[] calculatedifferday (CALENDAR C1,  CALENDAR C2) {int[] p1 = { c1.get (calendar.year),  c1.get (Calendar.MONTH),  c1.get (Calendar.day_of_month)  };int[] p2 = { c2.get (Calendar.YEAR),  c2.get (Calendar.month),  c2.get (Calendar.day_of_month)  }; System.out.println ("p1[0]="  + p1[0] +  " p1[1]="  + p1[1] +  "  P1[2]= " + p1[2]); System.out.println ("p2[0]="  + p2[0] +  " p2[1]="  + p2[1] +  "  P2[2]= " + p2[2]);int year = p2[0] - p1[0];int month =  (p2[0]  * 12)  + p2[1] -  ((p1[0] * 12)  + p1[1]); int day =   (int)   ((C2.gettimeinmillis () &Nbsp;- c1.gettimeinmillis ())  /  (24 * 60 * 60 * 1000)); return  new int[] { year, month, day };} /** *  Get date first day of week  *  *  @param  c *  @return  */public  Static calendar getlastdayofweek (calendar c) {//simpledateformat format2 = new  simpledateformat ("Y year M month D Day  e h m minute s seconds",  locale.china);//system.out.println ("Current Time:"  +  format2.format (C.gettime ())); C.set (Calendar.day_of_week, calendar.monday);//System.out.println (" Monday Time: " + format2.format (C.gettime ())); return c;} /** *  date plus minus  *  @param  c *  @param  day *  @return  */public  static calendar addordecreaseday (calendar c, int day) {C.add (Calendar.DAY_OF_ Month, day); return c;} /** *  get the last day of the month  *  @param  year *  @param  month *&nBSP; @return  */public static int getlastdayofmonth (Int year, int month) { Calendar c = calendar.getinstance (); C.set (year, month - 1, 1);return  C.getactualmaximum (calendar.day_of_month);} /** *  get the last day of the month  *  @param  cal *  @return  */public static int  getlastdayofmonth (calendar cal) {return cal.getactualmaximum (calendar.day_of_month);}}

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Java date operation, date, Calendar operation