The operation of time in Java (hope to criticize ...)

Code Demo:

Date to go in the database

Date s = list.get (0). Getsdate ();

System.out.println (s);//Tue APR 00:00:00 CST 2015

Manual New

Date d = new Date ();

System.out.println (d);//Tue APR 20:53:15 CST 2015

System.out.println ("+ +" + s.after (d));

Use the Calendar

Calendar calendar = Calendar.getinstance ();

Date time = Calendar.gettime ();

System.out.println (time);//Tue APR 20:55:16 CST 2015

Use date formatting

SimpleDateFormat format = new SimpleDateFormat ("Yyyy/mm/dd");

String FORMAT2 = Format.format (s);

System.out.println ("Format2" + format2);//2015/04/28

Re-parse

Date parse = Format.parse (FORMAT2);

System.out.println ("parse" + parse);//Tue APR 00:00:00 CST 2015

System.out.println ("???" + (S.gettime () >= parse.gettime ()));//True
Using Jodatime

DateTime dt = new DateTime ();

SYSTEM.OUT.PRINTLN (DT);//2015-04-28t21:00:28.780+08:00

System.out.println (Dt.todate ());//Tue APR 21:00:28 CST 2015

2 methods were written to handle:

1. Compare the 2 date sizes (only compared to the day of the year)/**  *  compares 2 dates, whether taken from a database or a new   *  @param  d1   *  @param  d2  *  @return   */ private String  Comparedate (DATE&NBSP;D1,DATE&NBSP;D2) {  if (d1==null | |  d2==null) {   return  "error";   }  long time1 = new  localdate (D1). ToDate (). GetTime ();   long time2 = new localdate (D2). ToDate () . GetTime ();   if (time1>time2) {   return  ">"   }else if (time1 ==time2) {   return  "= =";  }else{   return  "<";   } }2. Compare 2 Date sizes (compare only the Month day part)//  only compare the size  private string comparedate (Date s, &NBSP;DATE&NBSP;D)  throws ParseException {  SimpleDateFormat format =  New simpledateformat ("Yyyy/mm/dd");  if  (FORMAT.PArse (Format.format (s)). GetTime ()  > format.parse (    format.format (d)). GetTime ())  {   return  ">";  } else if  (Format.parse ( Format.format (s)). GetTime ()  == format.parse (    format.format (d)). GetTime ())  {   return  "= =";  } else {   return  "<";   } }

Have found the problem can leave a message, beginners forgive

The operation of time in Java (hope to criticize ...)