Making Java DateFormat work for Shorter Values

Question

I have a program which reads a Dateformat from user once and for all at the beginning of program such as yyyy/MM/dd HH:mm:ss a

Later on the program parses a File and use the Dateformat for all dates in the file. But recently I got a file, where 99% of the dates were 2014/09/01 12:00:04 AM So The user can input yyyy/MM/dd HH:mm:ss a.

However one date in that file is simply 2014/09/01 where the date format yyyy/MM/dd HH:mm:ss a fails.

Why can't yyyy/MM/dd HH:mm:ss a format shorter dates such as in the format yyyy/MM/dd.

What I want is that the java program use the format yyyy/MM/dd HH:mm:ss a to parse the following two dates below:

1. 2014/09/01 12:00:04 AM
2. 2014/09/01

Thanks

Answer 1

You have to use two formats. Check the example below

DateFormat df = new DateFormat() {
      static final String FORMAT1 = "yyyy/MM/dd HH:mm:ss";
      static final String FORMAT2 = "yyyy/MM/dd";
      final SimpleDateFormat sdf1 = new SimpleDateFormat(FORMAT1);
      final SimpleDateFormat sdf2 = new SimpleDateFormat(FORMAT2);

      @Override
      public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
          return null;
      }

      @Override
      public Date parse(String source, ParsePosition pos) {
           if (source.length() - pos.getIndex() == FORMAT1.length())
                 return sdf1.parse(source, pos);
           return sdf2.parse(source, pos);
      }
};
System.out.println(df.parse("2014/09/01 12:00:04 AM"));
System.out.println(df.parse("2014/09/01"));