Friday, February 09, 2007

Java isDate Date Checker

Here is an earlier post, showing what what proposed as one solution to the Java isDate() problem:

Below is a method that simulates the Visual Basic isDate() method and is configurable so you can set what you consider are the valid date formats.
I modifed this and added the "Jan|Feb|Mar|Apr..." and "JAN|FEB|MAR|APR|..." to the regex so that the method now validates the formats I needed to check.
I am now implementing this in my application.
See this code in my earlier blog post.

However, since that time, I worked out the below which has worked wonders and I am posting it here for any others who may need such a simple tool as to convert a text string to a Date object or check if a string is a valid Date, etc. Let me know if anyone found this useful:

First load the different type of date formats that you consider valid formats:
public static ArrayList loadFormats() {

ArrayList dateFormats = new ArrayList();
dateFormats.add(new SimpleDateFormat("yyyy-MM-dd"));
dateFormats.add(new SimpleDateFormat("yyyy MM dd"));
dateFormats.add(new SimpleDateFormat("yyyy.MM.dd"));
dateFormats.add(new SimpleDateFormat("yyyy-MMM-dd"));
dateFormats.add(new SimpleDateFormat("yyyy MMM dd"));
dateFormats.add(new SimpleDateFormat("yyyy.MMM.dd"));
dateFormats.add(new SimpleDateFormat("dd-MM-yyyy"));
dateFormats.add(new SimpleDateFormat("dd MM yyyy"));
dateFormats.add(new SimpleDateFormat("dd.MM.yyyy"));
dateFormats.add(new SimpleDateFormat("dd/MM/yyyy"));
dateFormats.add(new SimpleDateFormat("dd-MM-yy"));
dateFormats.add(new SimpleDateFormat("dd MM yy"));
dateFormats.add(new SimpleDateFormat("dd.MM.yy"));
dateFormats.add(new SimpleDateFormat("dd/MM/yy"));
dateFormats.add(new SimpleDateFormat("dd-MMM-yy"));
dateFormats.add(new SimpleDateFormat("dd MMM yy"));
dateFormats.add(new SimpleDateFormat("dd.MMM.yy"));
dateFormats.add(new SimpleDateFormat("dd/MMM/yy"));
dateFormats.add(new SimpleDateFormat("dd-MMM-yyyy"));
dateFormats.add(new SimpleDateFormat("dd MMM yyyy"));
dateFormats.add(new SimpleDateFormat("dd.MMM.yyyy"));
dateFormats.add(new SimpleDateFormat("dd/MMM/yyyy"));
dateFormats.add(new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy MM dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy.MM.dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy/MM/dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy-MMM-dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy MMM dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy.MMM.dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("yyyy/MMM/dd hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd-MM-yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd MM yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd.MM.yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd/MM/yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd MMM yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd.MMM.yyyy hh:mm:ss"));
dateFormats.add(new SimpleDateFormat("dd/MMM/yyyy hh:mm:ss"));

return dateFormats;

Next create your isDate method:
public static boolean isDate(String date) {

// Load formats
ArrayList dateFormats = loadFormats();

boolean validDate = false;
Date myDate = null;

Object[] myDateFormats = dateFormats.toArray();
for (int i = 0; i
SimpleDateFormat myFormat = (SimpleDateFormat) myDateFormats[i];
try {
myDate = myFormat.parse(date);
validDate = true;
catch (Exception e) {
validDate = false;
return validDate;
Here is a converter from String to Date to ensures it is a valid format:
public static Date convertStringToDate(String date) {

// Load formats
ArrayList dateFormats = loadFormats();

boolean validDate = false;
Date myDate = null;

Object[] myDateFormats = dateFormats.toArray();
for (int i = 0; i < myformat =" (SimpleDateFormat)" mydate =" myFormat.parse(date);" validdate =" true;" validdate =" false;">
There you go!