Get the current date using the Java Calendar Object _java

Ideas:

Get the start and end dates of the current quarter, pushing forward 3 months, the start and end dates of the previous quarter, on the basis of the current date

/** * @param flag true: start date; false: End date * @return/public static String Getlastquartertime (Boolean flag) {
    SimpleDateFormat shortsdf = new SimpleDateFormat ("Yyyy-mm-dd");
     
    SimpleDateFormat longsdf = new SimpleDateFormat ("Yyyy-mm-dd HH:mm:ss");
    String resultdate= "";
    Date now = null;
      try {Calendar calendar = calendar.getinstance ();
      int currentmonth = Calendar.get (calendar.month) + 1; true: start date; false: End date if (flag) {if (currentmonth >= 1 && currentmonth <= 3) Calenda
        R.set (calendar.month, 0);
        else if (currentmonth >= 4 && currentmonth <= 6) Calendar.set (Calendar.month, 3);
        else if (currentmonth >= 7 && currentmonth <= 9) Calendar.set (Calendar.month, 6);
        else if (currentmonth >= && currentmonth <=) calendar.set (Calendar.month, 9);
         
        Calendar.set (calendar.date, 1); now = LonGsdf.parse (Shortsdf.format (Calendar.gettime ()) + "00:00:00");
          }else{if (currentmonth >= 1 && currentmonth <= 3) {Calendar.set (Calendar.month, 2);
        Calendar.set (Calendar.date, 31);
          else if (currentmonth >= 4 && currentmonth <= 6) {Calendar.set (Calendar.month, 5);
        Calendar.set (Calendar.date, 30);
          else if (currentmonth >= 7 && currentmonth <= 9) {Calendar.set (calendar.month, 8);
        Calendar.set (Calendar.date, 30);
          else if (currentmonth >= && currentmonth <=) {calendar.set (calendar.month, 11);
        Calendar.set (Calendar.date, 31);
      now = Longsdf.parse (Shortsdf.format (Calendar.gettime ()) + "23:59:59");
      Calendar.settime (now);//Set Date Calendar.add (Calendar.month,-3);
       
    Resultdate = Longsdf.format (Calendar.gettime ());
    catch (Exception e) {; } rEturn resultdate;
 }