Java Date class and SimpleDateFormat class

1  Public classDemo6_date {2 3     /*4 * A: class date indicates a specific moment, accurate to milliseconds5 * B: Construction method6 * Public date () No parameter represents the current time7 * Public date (long date) when parameters are passed in to obtain a specific time8 * C: Member Method9 * Public long getTime () Gets the millisecond value of the time, similar to System.currenttimemillis ()Ten * public void settime (long time) One      *   A      */ -      Public Static voidMain (string[] args) { -         //demo1 (); theDate d =NewDate (); -System.out.println (D.gettime ());//1529382803822 -System.out.println (System.currenttimemillis ());//1529382803822 -          +     } -  +      Public Static voiddemo1 () { ADate D1 =NewDate (); atSystem.out.println (D1);//Tue June 12:29:27 CST 2018 -Date D2 =NewDate (0); -System.out.println (D2);//Thu Jan 08:00:00 CST 1970 constructs an incoming parameter of 0 o'clock, returns the January 1, 1970, the reason is 8 points, because our Beijing East eight district -     } -}

1  Public classDemo7_simpledateformat {2 3     /*4 * Its parent class is DateFormat is an abstract class5 * B: Construction method6 * Public SimpleDateFormat ()7 * Public SimpleDateFormat (String pattern) pattern-describes patterns for date and time formats8 * C: Member Method9 * Public final string format (date date) formats the given date as a datetime stringTen * Public Date Parse (string source) parses the string literal, generating a Date object One      */  A      Public Static voidMain (string[] args)throwsParseException { -   -         //demo1 (); the         //Demo2 (); -String s = "June 06, 2017 06:06:06"; -SimpleDateFormat SDF =NewSimpleDateFormat ("yyyy mm month DD Day HH:MM:SS"); -Date d =Sdf.parse (s); +System.out.println (d);//Tue June 06:06:06 CST -     } +  A      Public Static voidDemo2 () { atDate d =NewDate ();//Get current Time -SimpleDateFormat SDF =NewSimpleDateFormat ("yyyy mm month DD Day HH:mm:ss");//Create date format class object -System.out.println (Sdf.format (d));//format a string date June 06, 2017 13:24:30 -     } -  -      Public Static voiddemo1 () { inDate d =NewDate ();//Get current Time -SimpleDateFormat SDF =NewSimpleDateFormat ();//Create date format class object toSystem.out.println (Sdf.format (d));//format a string date 17-6-6 pm 1:17 +     } -  the}

1 /*2 * Get the current time how many days you were born3 * 1. Put the current date and your birthday in string type first4 * 2. Format the two string as a Date object5 * 3. Get the millisecond difference of two objects6 * 4. The total number of days divided by the conversion millisecond difference (1000*60*60*24)7      */8      Public Static voidMain (string[] args)throwsParseException {9 TenString today = "June 06, 2017"; OneString birthday = "June 06, 1998"; ASimpleDateFormat SDF =NewSimpleDateFormat ("yyyy mm month DD Day"); -Date D1 =Sdf.parse (today); -Date D2 =sdf.parse (birthday); theSystem.out.println (D1.gettime ()-d2.gettime ()); -         LongTime = D1.gettime ()-d2.gettime (); -System.out.println (time/1000/60/60/24); -}

Java Date class and SimpleDateFormat class