Year.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ---------
* Year.java
* ---------
* (C) Copyright 2001-2022, by David Gilbert.
*
* Original Author: David Gilbert;
* Contributor(s): -;
*
*/
package org.jfree.data.time;
import java.io.Serializable;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
/**
* Represents a year in the range -9999 to 9999. This class is immutable,
* which is a requirement for all {@link RegularTimePeriod} subclasses.
*/
public class Year extends RegularTimePeriod implements Serializable {
/**
* The minimum year value.
*
* @since 1.0.11
*/
public static final int MINIMUM_YEAR = -9999;
/**
* The maximum year value.
*
* @since 1.0.11
*/
public static final int MAXIMUM_YEAR = 9999;
/** For serialization. */
private static final long serialVersionUID = -7659990929736074836L;
/** The year. */
private short year;
/** The first millisecond. */
private long firstMillisecond;
/** The last millisecond. */
private long lastMillisecond;
/**
* Creates a new {@code Year}, based on the current system date/time.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*/
public Year() {
this(new Date());
}
/**
* Creates a time period representing a single year.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param year the year.
*/
public Year(int year) {
if ((year < Year.MINIMUM_YEAR) || (year > Year.MAXIMUM_YEAR)) {
throw new IllegalArgumentException(
"Year constructor: year (" + year + ") outside valid range.");
}
this.year = (short) year;
peg(getCalendarInstance());
}
/**
* Creates a new {@code Year}, based on a particular instant in time.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param time the time ({@code null} not permitted).
*
* @see #Year(Date, TimeZone, Locale)
*/
public Year(Date time) {
this(time, getCalendarInstance());
}
/**
* Creates a new {@code Year} instance, for the specified time zone
* and locale.
*
* @param time the current time ({@code null} not permitted).
* @param zone the time zone.
* @param locale the locale.
*
* @since 1.0.12
*/
public Year(Date time, TimeZone zone, Locale locale) {
Calendar calendar = Calendar.getInstance(zone, locale);
calendar.setTime(time);
this.year = (short) calendar.get(Calendar.YEAR);
peg(calendar);
}
/**
* Constructs a new instance, based on a particular date/time.
* The time zone and locale are determined by the {@code calendar}
* parameter.
*
* @param time the date/time ({@code null} not permitted).
* @param calendar the calendar to use for calculations ({@code null} not permitted).
*/
public Year(Date time, Calendar calendar) {
calendar.setTime(time);
this.year = (short) calendar.get(Calendar.YEAR);
peg(calendar);
}
/**
* Returns the year.
*
* @return The year.
*/
public int getYear() {
return this.year;
}
/**
* Returns the first millisecond of the year. This will be determined
* relative to the time zone specified in the constructor, or in the
* calendar instance passed in the most recent call to the
* {@link #peg(Calendar)} method.
*
* @return The first millisecond of the year.
*
* @see #getLastMillisecond()
*/
@Override
public long getFirstMillisecond() {
return this.firstMillisecond;
}
/**
* Returns the last millisecond of the year. This will be
* determined relative to the time zone specified in the constructor, or
* in the calendar instance passed in the most recent call to the
* {@link #peg(Calendar)} method.
*
* @return The last millisecond of the year.
*
* @see #getFirstMillisecond()
*/
@Override
public long getLastMillisecond() {
return this.lastMillisecond;
}
/**
* Recalculates the start date/time and end date/time for this time period
* relative to the supplied calendar (which incorporates a time zone).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @since 1.0.3
*/
@Override
public void peg(Calendar calendar) {
this.firstMillisecond = getFirstMillisecond(calendar);
this.lastMillisecond = getLastMillisecond(calendar);
}
/**
* Returns the year preceding this one.
* No matter what time zone and locale this instance was created with,
* the returned instance will use the default calendar for time
* calculations, obtained with {@link RegularTimePeriod#getCalendarInstance()}.
*
* @return The year preceding this one (or {@code null} if the
* current year is -9999).
*/
@Override
public RegularTimePeriod previous() {
if (this.year > Year.MINIMUM_YEAR) {
return new Year(this.year - 1);
}
else {
return null;
}
}
/**
* Returns the year following this one.
* No matter what time zone and locale this instance was created with,
* the returned instance will use the default calendar for time
* calculations, obtained with {@link RegularTimePeriod#getCalendarInstance()}.
*
* @return The year following this one (or {@code null} if the current
* year is 9999).
*/
@Override
public RegularTimePeriod next() {
if (this.year < Year.MAXIMUM_YEAR) {
return new Year(this.year + 1);
}
else {
return null;
}
}
/**
* Returns a serial index number for the year.
* <P>
* The implementation simply returns the year number (e.g. 2002).
*
* @return The serial index number.
*/
@Override
public long getSerialIndex() {
return this.year;
}
/**
* Returns the first millisecond of the year, evaluated using the supplied
* calendar (which determines the time zone).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @return The first millisecond of the year.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getFirstMillisecond(Calendar calendar) {
calendar.set(this.year, Calendar.JANUARY, 1, 0, 0, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendar.getTimeInMillis();
}
/**
* Returns the last millisecond of the year, evaluated using the supplied
* calendar (which determines the time zone).
*
* @param calendar the calendar ({@code null} not permitted).
*
* @return The last millisecond of the year.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getLastMillisecond(Calendar calendar) {
calendar.set(this.year, Calendar.DECEMBER, 31, 23, 59, 59);
calendar.set(Calendar.MILLISECOND, 999);
return calendar.getTimeInMillis();
}
/**
* Tests the equality of this {@code Year} object to an arbitrary
* object. Returns {@code true} if the target is a {@code Year}
* instance representing the same year as this object. In all other cases,
* returns {@code false}.
*
* @param obj the object ({@code null} permitted).
*
* @return {@code true} if the year of this and the object are the
* same.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Year)) {
return false;
}
Year that = (Year) obj;
return (this.year == that.year);
}
/**
* Returns a hash code for this object instance. The approach described by
* Joshua Bloch in "Effective Java" has been used here:
* <p>
* {@code http://developer.java.sun.com/developer/Books/effectivejava
* /Chapter3.pdf}
*
* @return A hash code.
*/
@Override
public int hashCode() {
int result = 17;
int c = this.year;
result = 37 * result + c;
return result;
}
/**
* Returns an integer indicating the order of this {@code Year} object
* relative to the specified object:
*
* negative == before, zero == same, positive == after.
*
* @param o1 the object to compare.
*
* @return negative == before, zero == same, positive == after.
*/
@Override
public int compareTo(Object o1) {
int result;
// CASE 1 : Comparing to another Year object
// -----------------------------------------
if (o1 instanceof Year) {
Year y = (Year) o1;
result = this.year - y.getYear();
}
// CASE 2 : Comparing to another TimePeriod object
// -----------------------------------------------
else if (o1 instanceof RegularTimePeriod) {
// more difficult case - evaluate later...
result = 0;
}
// CASE 3 : Comparing to a non-TimePeriod object
// ---------------------------------------------
else {
// consider time periods to be ordered after general objects
result = 1;
}
return result;
}
/**
* Returns a string representing the year..
*
* @return A string representing the year.
*/
@Override
public String toString() {
return Integer.toString(this.year);
}
/**
* Parses the string argument as a year.
* <P>
* The string format is YYYY.
*
* @param s a string representing the year.
*
* @return {@code null} if the string is not parseable, the year
* otherwise.
*/
public static Year parseYear(String s) {
// parse the string...
int y;
try {
y = Integer.parseInt(s.trim());
}
catch (NumberFormatException e) {
throw new TimePeriodFormatException("Cannot parse string.");
}
// create the year...
try {
return new Year(y);
}
catch (IllegalArgumentException e) {
throw new TimePeriodFormatException("Year outside valid range.");
}
}
}