Universal Date Parser.

It is easy to read the Date object from a string in Java. The task can be quite tricky when you are dealing with a third party data feed and you are not really sure about the format in which the date is going to come.

The below example handles most of the date formats and returns the date object. The format supported are [dd MMM,yy], [MM/dd/yy], [MMddyy], [yyyy-MM-dd], [dd-MMM-yy], [dd MMM yy], [MMM dd, yy], [yyyyMMdd].

You can easily add more formats but needs to make sure they and not conflicted with the existing things. For example you should not add [dd/MM/yy] as it will conflict with [MM/dd/yy] but it can be replaced. 

	import java.text.SimpleDateFormat;
	import java.util.Date;
	import java.util.HashMap;
	import java.util.Iterator;
	public class DateParserTest {
	/**
	* @param args
	*/
	public static void main(String[] args) {
	System.out.println(parseDate("May 3, 2010"));
	System.out.println(parseDate("5/3/2010"));
	System.out.println(parseDate("05032010"));
	System.out.println(parseDate("3 May 2010"));
	System.out.println(parseDate("3-May-2010"));
	}
	/**
	* Parses the String gives to give the Date object. Accepts the strict
	* patterns [dd MMM,yy],[MM/dd/yy],[MMddyy],[yyyy-MM-dd],[dd-MMM-yy],[MMM
	* dd,yy]
	*
	* @param dtStr
	* @return
	* @throws ParseException
	*/
	public static Date parseDate(String dtStr) {
	Date date = null;
	if (dtStr != null && !dtStr.trim().equals("")) {
	dtStr = dtStr.trim();
	} else {
	return null;
	}
	SimpleDateFormat formatter1 = new SimpleDateFormat("dd MMM,yy");
	formatter1.setLenient(false);
	SimpleDateFormat formatter2 = new SimpleDateFormat("MM/dd/yy");
	formatter2.setLenient(false);
	SimpleDateFormat formatter3 = new SimpleDateFormat("MMddyy");
	formatter3.setLenient(false);
	SimpleDateFormat formatter4 = new SimpleDateFormat("yyyy-MM-dd");
	formatter4.setLenient(false);
	SimpleDateFormat formatter5 = new SimpleDateFormat("dd-MMM-yy");
	formatter5.setLenient(false);
	SimpleDateFormat formatter6 = new SimpleDateFormat("dd MMM yy");
	formatter6.setLenient(false);
	SimpleDateFormat formatter7 = new SimpleDateFormat("MMM dd, yy");
	formatter7.setLenient(false);
	SimpleDateFormat formatter8 = new SimpleDateFormat("yyyyMMdd");
	formatter8.setLenient(false);
	HashMap<SimpleDateFormat, Date> formatMap = new HashMap<SimpleDateFormat, Date>();
	formatMap.put(formatter1, null);
	formatMap.put(formatter2, null);
	formatMap.put(formatter3, null);
	formatMap.put(formatter4, null);
	formatMap.put(formatter5, null);
	formatMap.put(formatter6, null);
	formatMap.put(formatter7, null);
	formatMap.put(formatter8, null);
	HashMap<SimpleDateFormat, Date> formatResMap = new HashMap<SimpleDateFormat, Date>();
	Iterator<SimpleDateFormat> itr = formatMap.keySet().iterator();
	while (itr.hasNext()) {
	SimpleDateFormat sdf = itr.next();
	try {
	date = (Date) sdf.parse(dtStr);
	} catch (Exception e) {
	date = null;
	}
	formatResMap.put(sdf, date);
	}
	Iterator<SimpleDateFormat> itr2 = formatResMap.keySet().iterator();
	while (itr2.hasNext()) {
	SimpleDateFormat sdf = itr2.next();
	if (formatResMap.get(sdf) != null) {
	date = formatResMap.get(sdf);
	}
	}
	return date;
	}
	}

view raw DateParserTest.java hosted with ❤ by GitHub