SimpleDateFormat使用AM / PM解析错误

Question

I am trying to parse input string date to Date. it is unable to detect AM/PM tag in the input. It should add time to specified date and return date. But its unable to parse AM/PM tag. 03:00 PM is parsed to 03:00:00 in Date. It should be 15:00:00.

output: Date : Tue Dec 22 03:00:00 UTC 2015 Calender : Tue Dec 22 11:15:00 UTC 2015 Result : 2015-12-22 11:15 AM

Am I using wrong date format?

Here's my code:

import java.util.*;
import java.text.*;
public class Main {
   public static void main(String[] args) throws Exception {
      System.out.println("Result : "+Main.addHoursToDate("2015-12-22 03:00 `enter code here`PM",8,15,0));
   }

   public static String addHoursToDate(String date, int hoursToAdd, int minsToAdd, int secToAdd){
        String result = "";
        try{
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm aa");
            Date dt = sdf.parse(date);

            System.out.println("Date : " + dt.toString());

            Calendar cl = Calendar.getInstance();
            cl.setTime(dt);
            cl.add(Calendar.HOUR_OF_DAY, hoursToAdd);
            cl.add(Calendar.MINUTE, minsToAdd);
            cl.add(Calendar.SECOND, secToAdd);

            SimpleDateFormat dfCal = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy");

            result = Main.formatDate(cl.getTime().toString(),"EEE MMM dd HH:mm:ss z yyyy","yyyy-MM-dd HH:mm aa");

            System.out.println("Calender : " + cl.getTime().toString());

        }catch(Exception e){
            return e.toString();
        }
        return result;
    }

  public static String formatDate(String date, String currentFormat, String requiredFormat) throws Exception {
        String result = "";
        boolean flag = false;
        try {
            SimpleDateFormat currentFormatter = new SimpleDateFormat(currentFormat);
            Date currentDate = currentFormatter.parse(date);

            flag = date.equals(currentFormatter.format(currentDate));
            if (!flag){
                throw new Exception();  // We are throwing this exception because the date has been parsed "successfully"  
                // but still we are not sure that it has been parsed "correctly"!!!
            }
            SimpleDateFormat requiredFormatter = new SimpleDateFormat(requiredFormat);
            result = requiredFormatter.format(currentDate);
        }catch (Exception e){
            return "";
        }

        return result;
    }

}

Answer 1

Got Answer myself:

I need to use

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm aa");

instead of

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm aa");

H : is used for 24 hour notation.

refer to https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html