- Java.util Package Classes
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- Java.util - ArrayDeque
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- Java.util - BitSet
- Java.util - Calendar
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- Java.util - Currency
- Java.util - Date
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- Java.util - EnumMap
- Java.util - EnumSet
- Java.util - Formatter
- Java.util - GregorianCalendar
- Java.util - HashMap
- Java.util - HashSet
- Java.util - Hashtable
- Java.util - IdentityHashMap
- Java.util - LinkedHashMap
- Java.util - LinkedHashSet
- Java.util - LinkedList
- Java.util - ListResourceBundle
- Java.util - Locale
- Java.util - Observable
- Java.util - PriorityQueue
- Java.util - Properties
- Java.util - PropertyPermission
- Java.util - PropertyResourceBundle
- Java.util - Random
- Java.util - ResourceBundle
- Java.util - ResourceBundle.Control
- Java.util - Scanner
- Java.util - ServiceLoader
- Java.util - SimpleTimeZone
- Java.util - Stack
- Java.util - StringTokenizer
- Java.util - Timer
- Java.util - TimerTask
- Java.util - TimeZone
- Java.util - TreeMap
- Java.util - TreeSet
- Java.util - UUID
- Java.util - Vector
- Java.util - WeakHashMap
- Java.util Package Extras
- Java.util - Interfaces
- Java.util - Exceptions
- Java.util - Enumerations
- Java.util Useful Resources
- Java.util - Useful Resources
- Java.util - Discussion
Java.util.GregorianCalendar.roll() Method
Description
The java.util.GregorianCalendar.roll(int field,boolean up) method adds or subtracts (up/down) a single unit of time on the given time field without changing larger fields.
Declaration
Following is the declaration for java.util.GregorianCalendar.roll() method
public void roll(int field,boolean up)
Parameters
up − indicates if the value of the specified calendar field is to be rolled up or rolled down. Use true if rolling up, false otherwise.
field − the time field.
Return Value
This method does not return a value.
Exception
IllegalArgumentException − if field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.
Example
The following example shows the usage of java.util.GregorianCalendar.roll() method.
package com.tutorialspoint; import java.util.*; public class GregorianCalendarDemo { public static void main(String[] args) { // create a new calendar GregorianCalendar cal = (GregorianCalendar) GregorianCalendar.getInstance(); // print the current date and time System.out.println("" + cal.getTime()); // roll a month cal.roll(GregorianCalendar.MONTH, true); System.out.println("Date:" + cal.getTime()); // roll a year backwards cal.roll(GregorianCalendar.YEAR, false); System.out.println("Date:" + cal.getTime()); } }
Let us compile and run the above program, this will produce the following result −
Fri May 18 13:31:57 EEST 2012 Date:Mon Jun 18 13:31:57 EEST 2012 Date:Sat Jun 18 13:31:57 EEST 2011