Hour.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.]
*
* ---------
* Hour.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;
import org.jfree.chart.internal.Args;
/**
* Represents an hour in a specific day. This class is immutable, which is a
* requirement for all {@link RegularTimePeriod} subclasses.
*/
public class Hour extends RegularTimePeriod implements Serializable {
/** For serialization. */
private static final long serialVersionUID = -835471579831937652L;
/** Useful constant for the first hour in the day. */
public static final int FIRST_HOUR_IN_DAY = 0;
/** Useful constant for the last hour in the day. */
public static final int LAST_HOUR_IN_DAY = 23;
/** The day. */
private Day day;
/** The hour. */
private byte hour;
/** The first millisecond. */
private long firstMillisecond;
/** The last millisecond. */
private long lastMillisecond;
/**
* Constructs a new Hour, based on the system date/time.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*/
public Hour() {
this(new Date());
}
/**
* Constructs a new Hour.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param hour the hour (in the range 0 to 23).
* @param day the day ({@code null} not permitted).
*/
public Hour(int hour, Day day) {
Args.nullNotPermitted(day, "day");
this.hour = (byte) hour;
this.day = day;
peg(getCalendarInstance());
}
/**
* Creates a new hour.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param hour the hour (0-23).
* @param day the day (1-31).
* @param month the month (1-12).
* @param year the year (1900-9999).
*/
public Hour(int hour, int day, int month, int year) {
this(hour, new Day(day, month, year));
}
/**
* Constructs a new instance, based on the supplied date/time.
* The time zone and locale are determined by the calendar
* returned by {@link RegularTimePeriod#getCalendarInstance()}.
*
* @param time the date-time ({@code null} not permitted).
*
* @see #Hour(Date, TimeZone, Locale)
*/
public Hour(Date time) {
// defer argument checking...
this(time, getCalendarInstance());
}
/**
* Constructs a new instance, based on the supplied date/time evaluated
* in the specified time zone.
*
* @param time the date-time ({@code null} not permitted).
* @param zone the time zone ({@code null} not permitted).
* @param locale the locale ({@code null} not permitted).
*
* @since 1.0.13
*/
public Hour(Date time, TimeZone zone, Locale locale) {
Args.nullNotPermitted(time, "time");
Args.nullNotPermitted(zone, "zone");
Args.nullNotPermitted(locale, "locale");
Calendar calendar = Calendar.getInstance(zone, locale);
calendar.setTime(time);
this.hour = (byte) calendar.get(Calendar.HOUR_OF_DAY);
this.day = new Day(time, zone, locale);
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 Hour(Date time, Calendar calendar) {
Args.nullNotPermitted(time, "time");
Args.nullNotPermitted(calendar, "calendar");
calendar.setTime(time);
this.hour = (byte) calendar.get(Calendar.HOUR_OF_DAY);
this.day = new Day(time, calendar);
peg(calendar);
}
/**
* Returns the hour.
*
* @return The hour (0 <= hour <= 23).
*/
public int getHour() {
return this.hour;
}
/**
* Returns the day in which this hour falls.
*
* @return The day.
*/
public Day getDay() {
return this.day;
}
/**
* Returns the year in which this hour falls.
*
* @return The year.
*/
public int getYear() {
return this.day.getYear();
}
/**
* Returns the month in which this hour falls.
*
* @return The month.
*/
public int getMonth() {
return this.day.getMonth();
}
/**
* Returns the day-of-the-month in which this hour falls.
*
* @return The day-of-the-month.
*/
public int getDayOfMonth() {
return this.day.getDayOfMonth();
}
/**
* Returns the first millisecond of the hour. 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 hour.
*
* @see #getLastMillisecond()
*/
@Override
public long getFirstMillisecond() {
return this.firstMillisecond;
}
/**
* Returns the last millisecond of the hour. 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 hour.
*
* @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 hour 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 hour preceding this one.
*/
@Override
public RegularTimePeriod previous() {
Hour result;
if (this.hour != FIRST_HOUR_IN_DAY) {
result = new Hour(this.hour - 1, this.day);
}
else { // we are at the first hour in the day...
Day prevDay = (Day) this.day.previous();
if (prevDay != null) {
result = new Hour(LAST_HOUR_IN_DAY, prevDay);
}
else {
result = null;
}
}
return result;
}
/**
* Returns the hour 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 hour following this one.
*/
@Override
public RegularTimePeriod next() {
Hour result;
if (this.hour != LAST_HOUR_IN_DAY) {
result = new Hour(this.hour + 1, this.day);
}
else { // we are at the last hour in the day...
Day nextDay = (Day) this.day.next();
if (nextDay != null) {
result = new Hour(FIRST_HOUR_IN_DAY, nextDay);
}
else {
result = null;
}
}
return result;
}
/**
* Returns a serial index number for the hour.
*
* @return The serial index number.
*/
@Override
public long getSerialIndex() {
return this.day.getSerialIndex() * 24L + this.hour;
}
/**
* Returns the first millisecond of the hour.
*
* @param calendar the calendar/timezone ({@code null} not permitted).
*
* @return The first millisecond.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getFirstMillisecond(Calendar calendar) {
int year = this.day.getYear();
int month = this.day.getMonth() - 1;
int dom = this.day.getDayOfMonth();
calendar.set(year, month, dom, this.hour, 0, 0);
calendar.set(Calendar.MILLISECOND, 0);
return calendar.getTimeInMillis();
}
/**
* Returns the last millisecond of the hour.
*
* @param calendar the calendar/timezone ({@code null} not permitted).
*
* @return The last millisecond.
*
* @throws NullPointerException if {@code calendar} is
* {@code null}.
*/
@Override
public long getLastMillisecond(Calendar calendar) {
int year = this.day.getYear();
int month = this.day.getMonth() - 1;
int dom = this.day.getDayOfMonth();
calendar.set(year, month, dom, this.hour, 59, 59);
calendar.set(Calendar.MILLISECOND, 999);
return calendar.getTimeInMillis();
}
/**
* Tests the equality of this object against an arbitrary Object.
* <P>
* This method will return true ONLY if the object is an Hour object
* representing the same hour as this instance.
*
* @param obj the object to compare ({@code null} permitted).
*
* @return {@code true} if the hour and day value of the object
* is the same as this.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Hour)) {
return false;
}
Hour that = (Hour) obj;
if (this.hour != that.hour) {
return false;
}
if (!this.day.equals(that.day)) {
return false;
}
return true;
}
/**
* Returns a string representation of this instance, for debugging
* purposes.
*
* @return A string.
*/
@Override
public String toString() {
return "[" + this.hour + "," + getDayOfMonth() + "/" + getMonth() + "/"
+ getYear() + "]";
}
/**
* 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;
result = 37 * result + this.hour;
result = 37 * result + this.day.hashCode();
return result;
}
/**
* Returns an integer indicating the order of this Hour 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 Hour object
// -----------------------------------------
if (o1 instanceof Hour) {
Hour h = (Hour) o1;
result = getDay().compareTo(h.getDay());
if (result == 0) {
result = this.hour - h.getHour();
}
}
// 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;
}
/**
* Creates an Hour instance by parsing a string. The string is assumed to
* be in the format "YYYY-MM-DD HH", perhaps with leading or trailing
* whitespace.
*
* @param s the hour string to parse.
*
* @return {@code null} if the string is not parseable, the hour
* otherwise.
*/
public static Hour parseHour(String s) {
Hour result = null;
s = s.trim();
String daystr = s.substring(0, Math.min(10, s.length()));
Day day = Day.parseDay(daystr);
if (day != null) {
String hourstr = s.substring(
Math.min(daystr.length() + 1, s.length()), s.length()
);
hourstr = hourstr.trim();
int hour = Integer.parseInt(hourstr);
// if the hour is 0 - 23 then create an hour
if ((hour >= FIRST_HOUR_IN_DAY) && (hour <= LAST_HOUR_IN_DAY)) {
result = new Hour(hour, day);
}
}
return result;
}
}