How do I validate a timestamp?

Question

my application takes in a string like this "2002-10-15 10:55:01.000000". I need to validate that the string is a valid for a db2 timestamp.

How can I do this?

EDIT: This mostly works

     public static boolean isTimeStampValid(String inputString) {
     SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
        try {
            format.parse(inputString);
            return true;
        } catch (ParseException e) {
            return false;
        }
     }

The problem is that if I pass it a bad format for milliseconds like "2011-05-02 10:10:01.0av" this will pass validation. I am assuming that since the first millisecond character is valid then it just truncates the rest of the string.

Solution 1

I'm not exactly sure about the format but you you can play around it and can try something like this

public static bool isTimeStampValid(String inputString)
{ 
    SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
    try{
       format.parse(inputString);
       return true;
    }
    catch(ParseException e)
    {
        return false;
    }
}

EDIT: if you want to validate for numbers after successful parsing, you could do

       format.parse(inputString);
       Pattern p = Pattern.compile("^\\d{4}[-]?\\d{1,2}[-]?\\d{1,2} \\d{1,2}:\\d{1,2}:\\d{1,2}[.]?\\d{1,6}$");
       return p.matcher(inputString).matches();

instead of

   format.parse(inputString);
   return true;

Solution 2

http://download.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html

I believe the format would be "yyyy-MM-dd HH:mm:ss.SSSSSS"

Call parse(String) and catch ParseException indicating it is invalid.

Solution 3

/**
 * This method validates the given time stamp in String format
 * @param timestamp
 * @return
 */

public static boolean isTimeStampValid(String timestamp) {
    //(Considering that formal will be yyyy-MM-dd HH:mm:ss.SSSSSS )
    //Tokenize string and separate date and time
    boolean time = false;
    try {
            //Tokenize string and separate date and time
            StringTokenizer st = new StringTokenizer(timestamp, " ");

            if (st.countTokens() != 2) {
                return false;
            }

            String[] dateAndTime = new String[2];

            int i = 0;
            while (st.hasMoreTokens()) {
                dateAndTime[i] = st.nextToken();
                i++;
            }

            String timeToken = dateAndTime[1];

            StringTokenizer timeTokens = new StringTokenizer(timeToken, ":");
            if (timeTokens.countTokens() != 3) {
                return false;
            }

            String[] timeAt = new String[4];
            int j = 0;
            while (timeTokens.hasMoreTokens()) {
                timeAt[j] = timeTokens.nextToken();
                j++;
            }
            try {
                    int HH = Integer.valueOf(timeAt[0].toString());
                    int mm = Integer.valueOf(timeAt[1].toString());
                    float ss = Float.valueOf(timeAt[2].toString());


                    if (HH < 60 && HH >= 0 && mm < 60 && mm >= 0 && ss < 60 && ss >= 0) {
                        time = true;
                    } else {
                    }
            } catch (Exception e) {
                e.printStackTrace();
            }
            //Got Date
            String dateToken = dateAndTime[0];//st.nextToken();

            //Tokenize separated date and separate year-month-day
            StringTokenizer dateTokens = new StringTokenizer(dateToken, "-");
            if (dateTokens.countTokens() != 3) {
                return false;
            }
            String[] tokenAt = new String[3];

            //This will give token string array with year month and day value.
            int k = 0;
            while (dateTokens.hasMoreTokens()) {
                tokenAt[k] = dateTokens.nextToken();
                k++;
            }

            //Now try to create new date with got value of date
            int dayInt = Integer.parseInt(tokenAt[2]);
            int monthInt = Integer.parseInt(tokenAt[1]);
            int yearInt = Integer.parseInt(tokenAt[0]);
            Calendar cal = new GregorianCalendar();
            cal.setLenient(false);
            cal.set(yearInt, monthInt - 1, dayInt);
            cal.getTime();//If not able to create date it will throw error



    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }
    //Here we ll check for correct format is provided else it ll return false
    try {
            Pattern p = Pattern.compile("^\\d{4}[-]?\\d{1,2}[-]?\\d{1,2} \\d{1,2}:\\d{1,2}:\\d{1,2}[.]?\\d{1,6}$");
            if (p.matcher(timestamp).matches()) {
            } else {
                return false;
            }

    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }
    //Cross checking with simple date format to get correct time stamp only
    SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
    try {
            format.parse(timestamp);
            //return true;

            if (time) {
                return true;
            } else {
                return false;
            }
    } catch (ParseException e) {
        e.printStackTrace();
        return false;
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }

}