How to get time in milliseconds in java using Date/Calendar class

There are two ways to get time in milliseconds in java.
1) Using public long getTime() method of Date class.
2) Using public long getTimeInMillis() method of Calendar class

Here is the complete self explanatory example: Do refer the comments in the program.

import java.util.Calendar;
import java.util.Date;
public class TimeDemo {
   public static void main(String[] args) 
   {
      //Date Object
      Date date = new Date();
      /*getTime():It returns the number of milliseconds since 
       * January 1, 1970, 00:00:00 GMT 
       * represented by this date.
       */
      long timeMilli = date.getTime();
      System.out.println("Time in milliseconds using Date class: " + timeMilli);

      //Calendar Object
      Calendar calendar = Calendar.getInstance();
      /*The method getTimeInMillis() returns the 
       * Calendar's time value in milliseconds.
       */
      long timeMilli2 = calendar.getTimeInMillis();
      System.out.println("Time in milliseconds using Calendar: " + timeMilli2);
   }
}

Output:

Time in milliseconds using Date class: 1389184553774
Time in milliseconds using Calendar: 1389184553818

References:

1. Date Javadoc
2. Calendar Javadoc