Java Format - Java Date Format Pattern

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SimpleDateFormat Date and time formats are specified by date and time pattern strings.

Within format strings, unquoted letters from 'A' to 'Z' and from 'a' to 'z' are treated as format letters representing the components of a date or time string.

Text can be quoted using single quotes (') to avoid interpretation. '' represents a single quote. All other characters are not interpreted and will be simply copied into the output string.

Pattern

The following pattern letters are defined:

Example

The following table has some example format string and its result.

Example 2

We can embed literals inside formatted dates.

We need to place them inside single quotes to treat them as literals.

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/*from ww  w .  j  a  va 2s  . c o  m*/
public class Main {
  public static void main(String[] args) {
    GregorianCalendar gc  = new GregorianCalendar(2010, Calendar.SEPTEMBER,9);
    Date  birthDate = gc.getTime();

    String pattern = "'I was born on the day' dd 'of the month 'MMMM 'in' yyyy";

    SimpleDateFormat simpleFormatter  = new SimpleDateFormat(pattern);
    System.out.println(simpleFormatter.format(birthDate));
  }

}

The code above generates the following result.

Parse String to Date

We can convert String value to date time value by using the parse() method of the SimpleDateFormat class.

The signature of the parse() method is as follows:

public Date parse(String text, ParsePosition startPos)

The parse() method takes two arguments. text is the string to parse, startPos sets the starting position of the character in the text from where you want to start parsing.

Example 3

The following code shows how parse a string to a date value.

import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
//  ww  w  . j a  v  a  2s  .com
public class Main {
  public static void main(String[] args) {
    String text = "09/19/2014";
    // Create a pattern for the date text "09/19/2014"
    String pattern = "MM/dd/yyyy";
    SimpleDateFormat simpleFormatter = new SimpleDateFormat(pattern);
    // a ParsePosition object with value zero
    ParsePosition startPos = new ParsePosition(0);
    // Parse the text
    Date parsedDate = simpleFormatter.parse(text, startPos);
    
    System.out.println(parsedDate);
  }

}

The code above generates the following result.

Example 4

The following code parses two date values from a single string.

import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
//  w w w  . j av a 2 s  . co  m
public class Main {
  public static void main(String[] args) {
    String text = "ab01/01/1999cd12/31/2000ef";
    String pattern = "MM/dd/yyyy";

    SimpleDateFormat simpleFormatter  = new SimpleDateFormat(pattern);

    // Set  the   start index   at 2
    ParsePosition startPos  = new ParsePosition(2);

    // Parse the   text to get   the   first date (January 1,  1999) 
    Date  firstDate = simpleFormatter.parse(text, startPos);
    System.out.println(firstDate);

   //Now, startPos has  its index set after the last  character of the first date parsed.
   
    int  currentIndex = startPos.getIndex();
    System.out.println(currentIndex);
    // To set its index   to the   next   date increment its index   by  2. 

    int  nextIndex = currentIndex + 2;
    startPos.setIndex  (nextIndex);

    // Parse the   text to get   the   second  date (December  31,   2000) 
    Date  secondDate = simpleFormatter.parse(text, startPos);
    System.out.println(secondDate);

  }

}

The code above generates the following result.

Example 5

The following code shows how to parse a Timestamp to Get Its Time Parts

import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
//from w  w  w . jav a2  s  .  c om
public class Main {
  public static void main(String[] args) {
    String input = "2014-05-04 09:10:40.321";

    // Prepare the pattern
    String pattern = "yyyy-MM-dd HH:mm:ss.SSS";

    SimpleDateFormat sdf = new SimpleDateFormat(pattern);

    // Parse the text into a Date object
    Date dt = sdf.parse(input, new ParsePosition(0));
    System.out.println(dt);

    // Get the Calendar instance
    Calendar cal = Calendar.getInstance();
    cal.setTime(dt);

    // Print time parts
    System.out.println("Hour:" + cal.get(Calendar.HOUR));
    System.out.println("Minute:" + cal.get(Calendar.MINUTE));
    System.out.println("Second:" + cal.get(Calendar.SECOND));
    System.out.println("Millisecond:" + cal.get(Calendar.MILLISECOND));

  }
}

The code above generates the following result.

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