getTime() and setTime(Date date) methods

class GregorianCalendar has two methods that are particularly handy for dealing with Date objects.

• Remember, Date deals solely in milliseconds since January 1, 1970.
• So, if you know the month, day, and year, but you want a Date object, you can use the GregorianCalendar to translate between the two.
• On the other hand, if you have a Date object, but need to know the month, day, and year, you can use GregorianCalendar to figure it out.
• So, Date stores the time, and GregorianCalendar is a translator.  Generally, Date is a better object to pass between objects than GregorianCalendar, because Date is not specific to one calendar.  Additionally, you will often find Java library objects that only accept dates as parameters.

// For purposes of demonstration, let's assume this is in an object named object1.
// One would hope that we would have more meaningfull names in a production program.

public void method1() {
    // Note, the year, month, and day would normally not be static numbers.
    // This is for demonstration purposes only.
    GregorianCalendar modifiedDate = new GregorianCalendar(2001, 9, 10);
 
    // perhaps some other code here...

    object2.method2(modifiedDate.getTime());
}

// For purposes of demonstration, let's assume this is in an object named object2.
// Note that this method accepts a Date object, not a GregorianCalendar object.

public void method2(Date date) {

    // make a new GregorianCalendar object.
    GregorianCalendar displayDate = new GregorianCalendar();
 
    // Basically, assign the date from the input to this GregorianCalendar object.
    displayDate.setTime(date);

    // Now, get the desired variables and print them out.
    int day = displayDate.get(Calendar.DATE);

    // Don't forget, Java starts counting months at 0.
    int month = displayDate.get(Calendar.MONTH) + 1;

    int year = displayDate.get(Calendar.YEAR);

    // Print an informational message to the user.
    System.out.println("The last modified date is: " + month + "/" + day + "/" + year);

    // And there you have it.
}


 An example.

Created by:  Brandan Jones January 4, 2002