Checking if date parsing is correct

Question

Hello,

I have this code for checking whether the Date is OK or not, but it's not ckecking all the cases. For example when text="03/13/2009" as this date doesn't exist in the format "dd/MM/yyyy" it parses the date as 03/01/2010. Is there any way to change this behaviour and getting an exception when I try to parse a Date which is not correct? What's the best way to do this validation?

public static final String DATE_PATTERN = "dd/MM/yyyy";

public static boolean isDate(String text){
     SimpleDateFormat formatter = new SimpleDateFormat(DATE_PATTERN);
     ParsePosition position = new ParsePosition(0);
     formatter.parse(text, position);
     if(position.getIndex() != text.length()){
         return false;
     }else{
        return true;
     }
}

Thanks.

Answer 1

In my opinion the best way to validate date is to use regular expression, you can find here many of them also for validating dates http://regexlib.com/DisplayPatterns.aspx Java has good support for regular expressions, some tutorial here http://java.sun.com/docs/books/tutorial/essential/regex/index.html

Answer 2

You need to set lenient to false before parsing, otherwise the parser will "guess" and try to correct invalid dates

formatter.setLenient(false);

Check out http://java.sun.com/j2se/1.5.0/docs/api/java/util/Calendar.html#setLenient(boolean)