Methods of the GregorianCalendar

• Many Java objects have getter and setter methods to obtain or change class data.
• For instance, getGallonsOfGas() is a standard way to get the value of the gallonsOfGas attribute.  Yes, the capitalization you see is proper.
• On the other hand, setGallonsOfGas(int gallonsOfGas) is the proper method to set the gallonsOfGas attribute.
• Curiously, the GregorianCalendar object acts in a similar, yet not identical way.  You have to use contstants of the GregorianCalendar class to get or set needed attributes.  A full list of these constants is available on the API doc.
• The following code gets a GregorianCalendar object, gets the hour, adds two to it, and then sets the hour.


GregorianCalendar expire = new GregorianCalendar();
int hour = expire.get(Calendar.HOUR);
hour += 2;
expire.set(Calendar.HOUR, hour);
 

• The above demonstrates the user of the get() and set() methods, along with constants.  However, if you really needed to add two hours to the time, you can simply use the add() method of the GregorianCalendar object.
expire.add(Calendar.HOUR, 2);
 
• To subtract two hours from the given time, simply use -2.


 getTime() and setTime(Date date) methods

Created by:  Brandan Jones January 4, 2002