Date Formatting in Java - three most Efficient ways

Date Formatting kinda very trivial. but i found some interesting as well as useful info to convert date objects in java into our own formatting..

Option #1 Using java.text.SimpleDateFormat

 Here it is the hierarchy structure of the class SimpleDateFormat.

 

SimpleDateFormat is a concrete subclass of DateFormat. It allows you to define your own formatting patterns that are used to display date and time information. It allows formatting (date -> text), parsing (text -> date), and normalization.One of its constructors is shown here:

SimpleDateFormat(String formatString)

The argument formatString describes how date and time information is displayed. An example of its use is given here:

SimpleDateFormat sdf = SimpleDateFormat("dd MMM yyyy hh:mm:ss zzz");

In most cases, the number of times a symbol is repeated determines how that data is presented. Text information is displayed in an abbreviated form if the pattern letter is repeated less than four times. Otherwise, the unabbreviated form is used. For example, a zzzz pattern can display Pacific Daylight Time, and a zzz pattern can display PDT. For numbers, the number of times a pattern letter is repeated determines how many digits are presented. For example, hh:mm:ss can present 01:51:15, but h:m:s displays the same time value as 1:51:15.

Finally, M or MM causes the month to be displayed as one or two digits. However, three or more repetitions of M cause the month to be displayed as a text string.

The following program shows how this class is used:

Example #1

// Demonstrate SimpleDateFormat.

import java.text.*;
import java.util.*;
public class SimpleDateFormatDemo {
public static void main(String args[]) {
Date date = new Date();
SimpleDateFormat sdf; sdf = new SimpleDateFormat("hh:mm:ss");
System.out.println(sdf.format(date));
sdf = new SimpleDateFormat("dd MMM yyyy hh:mm:ss zzz");
System.out.println(sdf.format(date));
sdf = new SimpleDateFormat("E MMM dd yyyy");
System.out.println(sdf.format(date));
}
}

Sample output from this program is shown here:

11:51:50
19 Feb 1999 11:51:50 CST
Fri Feb 19 1999

Example #2

Parsing a request Date String into Date object, and then format it according to your need:

private SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd");
private SimpleDateFormat sdf2 = new SimpleDateFormat("MM/dd/yy");

//Parses text from a string to produce a Date.
Date checkInDate = sdf2.parse("06/05/2013");
object1.setCheckInDate(sdf1.format(checkInDate));

Option #2 Using java.text.DateFormat

import java.text.DateFormat;

import java.util.Date;

public class DateFormatExample1 {

public static void main(String[] args) {
// Make a new Date object. It will be initialized to the current date.
Date now = new Date();

// See what toString() returns
System.out.println(" 1. " + now.toString());

// Next, try the default DateFormat
System.out.println(" 2. " + DateFormat.getInstance().format(now));

// And the default time and date-time DateFormats
System.out.println(" 3. " + DateFormat.getTimeInstance().format(now));   
System.out.println(" 4. " + DateFormat.getDateTimeInstance().format(now));

// Next, try the short, medium and long variants of the default time format
System.out.println(" 5. " + DateFormat.getTimeInstance(DateFormat.SHORT).format(now));
System.out.println(" 6. " + DateFormat.getTimeInstance(DateFormat.MEDIUM).format(now));
System.out.println(" 7. " + DateFormat.getTimeInstance(DateFormat.LONG).format(now));

// For the default date-time format, the length of both the date and time elements can be specified. Here are some examples:
System.out.println(" 8. " + DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT).format(now));
System.out.println(" 9. " + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.SHORT).format(now));
System.out.println("10. " + DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG).format(now));

}
}

When you run this class, you will see output that looks something like that shown in

1. Tue Nov 04 20:14:11 EST 2003
2. 11/4/03 8:14 PM
3. 8:14:11 PM
4. Nov 4, 2003 8:14:11 PM
5. 8:14 PM
6. 8:14:11 PM
7. 8:14:11 PM EST
8. 11/4/03 8:14 PM
9. Nov 4, 2003 8:14 PM
10. November 4, 2003 8:14:11 PM EST

Option #3 Using java.text.Format

Format formatter;

// The year
formatter = new SimpleDateFormat("yy");    // 02
formatter = new SimpleDateFormat("yyyy");  // 2002

// The month
formatter = new SimpleDateFormat("M");     // 1
formatter = new SimpleDateFormat("MM");    // 01
formatter = new SimpleDateFormat("MMM");   // Jan
formatter = new SimpleDateFormat("MMMM");  // January

// The day
formatter = new SimpleDateFormat("d");     // 9
formatter = new SimpleDateFormat("dd");    // 09

// The day in week
formatter = new SimpleDateFormat("E");     // Wed
formatter = new SimpleDateFormat("EEEE");  // Wednesday

// Get today's date
Date date = new Date();

// Some examples
formatter = new SimpleDateFormat("MM/dd/yy");
String s = formatter.format(date);
// 01/09/02

formatter = new SimpleDateFormat("dd-MMM-yy");
s = formatter.format(date);
// 29-Jan-02

// Examples with date and time; see also
// Formatting the Time Using a Custom Format
formatter = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss");
s = formatter.format(date);
// 2002.01.29.08.36.33

formatter = new SimpleDateFormat("E, dd MMM yyyy HH:mm:ss Z");
s = formatter.format(date);
// Tue, 09 Jan 2002 22:14:02 -0500