Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2014, by Object Refinery Limited 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.] * * ---------------- * Millisecond.java * ---------------- * (C) Copyright 2001-2014, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 11-Oct-2001 : Version 1 (DG); * 19-Dec-2001 : Added new constructors as suggested by Paul English (DG); * 26-Feb-2002 : Added new getStart() and getEnd() methods (DG); * 29-Mar-2002 : Fixed bug in getStart(), getEnd() and compareTo() methods (DG); * 10-Sep-2002 : Added getSerialIndex() method (DG); * 07-Oct-2002 : Fixed errors reported by Checkstyle (DG); * 10-Jan-2003 : Changed base class and method names (DG); * 13-Mar-2003 : Moved to com.jrefinery.data.time package and implemented * Serializable (DG); * 21-Oct-2003 : Added hashCode() method (DG); * ------------- JFREECHART 1.0.x --------------------------------------------- * 05-Oct-2006 : Updated API docs (DG); * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG); * 04-Apr-2007 : In Millisecond(Date, TimeZone), peg milliseconds to the * specified zone (DG); * 06-Jun-2008 : Added handling for general RegularTimePeriod in compareTo() * method: * see http://www.jfree.org/phpBB2/viewtopic.php?t=24805 (DG); * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE (DG); * 02-Mar-2009 : Added new constructor with Locale (DG); * */ 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.util.ParamChecks; /** * Represents a millisecond. This class is immutable, which is a requirement * for all {@link RegularTimePeriod} subclasses. */ public class Millisecond extends RegularTimePeriod implements Serializable, Comparable<TimePeriod> { /** For serialization. */ static final long serialVersionUID = -5316836467277638485L; /** A constant for the first millisecond in a second. */ public static final int FIRST_MILLISECOND_IN_SECOND = 0; /** A constant for the last millisecond in a second. */ public static final int LAST_MILLISECOND_IN_SECOND = 999; /** The day. */ private Day day; /** The hour in the day. */ private byte hour; /** The minute. */ private byte minute; /** The second. */ private byte second; /** The millisecond. */ private int millisecond; /** * The pegged millisecond. */ private long firstMillisecond; /** * Constructs a millisecond based on the current system time. */ public Millisecond() { this(new Date()); } /** * Constructs a millisecond. * * @param millisecond the millisecond (0-999). * @param second the second. */ public Millisecond(int millisecond, Second second) { this.millisecond = millisecond; this.second = (byte) second.getSecond(); this.minute = (byte) second.getMinute().getMinute(); this.hour = (byte) second.getMinute().getHourValue(); this.day = second.getMinute().getDay(); peg(Calendar.getInstance()); } /** * Creates a new millisecond. * * @param millisecond the millisecond (0-999). * @param second the second (0-59). * @param minute the minute (0-59). * @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 Millisecond(int millisecond, int second, int minute, int hour, int day, int month, int year) { this(millisecond, new Second(second, minute, hour, day, month, year)); } /** * Constructs a new millisecond using the default time zone. * * @param time the time. * * @see #Millisecond(Date, TimeZone, Locale) */ public Millisecond(Date time) { this(time, TimeZone.getDefault(), Locale.getDefault()); } /** * Creates a millisecond. * * @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 Millisecond(Date time, TimeZone zone, Locale locale) { Calendar calendar = Calendar.getInstance(zone, locale); calendar.setTime(time); this.millisecond = calendar.get(Calendar.MILLISECOND); this.second = (byte) calendar.get(Calendar.SECOND); this.minute = (byte) calendar.get(Calendar.MINUTE); this.hour = (byte) calendar.get(Calendar.HOUR_OF_DAY); this.day = new Day(time, zone, locale); peg(calendar); } /** * Returns the second. * * @return The second. */ public Second getSecond() { return new Second(this.second, this.minute, this.hour, this.day.getDayOfMonth(), this.day.getMonth(), this.day.getYear()); } /** * Returns the millisecond. * * @return The millisecond. */ public long getMillisecond() { return this.millisecond; } /** * Returns the first millisecond of the second. 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 second. * * @see #getLastMillisecond() */ @Override public long getFirstMillisecond() { return this.firstMillisecond; } /** * Returns the last millisecond of the second. 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 second. * * @see #getFirstMillisecond() */ @Override public long getLastMillisecond() { return this.firstMillisecond; } /** * 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</code> not permitted). * * @since 1.0.3 */ @Override public void peg(Calendar calendar) { this.firstMillisecond = getFirstMillisecond(calendar); } /** * Returns the millisecond preceding this one. * * @return The millisecond preceding this one. */ @Override public RegularTimePeriod previous() { RegularTimePeriod result = null; if (this.millisecond != FIRST_MILLISECOND_IN_SECOND) { result = new Millisecond(this.millisecond - 1, getSecond()); } else { Second previous = (Second) getSecond().previous(); if (previous != null) { result = new Millisecond(LAST_MILLISECOND_IN_SECOND, previous); } } return result; } /** * Returns the millisecond following this one. * * @return The millisecond following this one. */ @Override public RegularTimePeriod next() { RegularTimePeriod result = null; if (this.millisecond != LAST_MILLISECOND_IN_SECOND) { result = new Millisecond(this.millisecond + 1, getSecond()); } else { Second next = (Second) getSecond().next(); if (next != null) { result = new Millisecond(FIRST_MILLISECOND_IN_SECOND, next); } } return result; } /** * Returns a serial index number for the millisecond. * * @return The serial index number. */ @Override public long getSerialIndex() { long hourIndex = this.day.getSerialIndex() * 24L + this.hour; long minuteIndex = hourIndex * 60L + this.minute; long secondIndex = minuteIndex * 60L + this.second; return secondIndex * 1000L + this.millisecond; } /** * Tests the equality of this object against an arbitrary Object. * <P> * This method will return true ONLY if the object is a Millisecond object * representing the same millisecond as this instance. * * @param obj the object to compare * * @return <code>true</code> if milliseconds and seconds of this and object * are the same. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof Millisecond)) { return false; } Millisecond that = (Millisecond) obj; if (this.millisecond != that.millisecond) { return false; } if (this.second != that.second) { return false; } if (this.minute != that.minute) { return false; } if (this.hour != that.hour) { return false; } if (!this.day.equals(that.day)) { return false; } return true; } /** * 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</code> * * @return A hashcode. */ @Override public int hashCode() { int result = 17; result = 37 * result + this.millisecond; result = 37 * result + getSecond().hashCode(); return result; } /** * Returns an integer indicating the order of this Millisecond object * relative to the specified object: * * negative == before, zero == same, positive == after. * * @param obj the object to compare * * @return negative == before, zero == same, positive == after. */ @Override public int compareTo(TimePeriod obj) { int result; long difference; // CASE 1 : Comparing to another Second object // ------------------------------------------- if (obj instanceof Millisecond) { Millisecond ms = (Millisecond) obj; difference = getFirstMillisecond() - ms.getFirstMillisecond(); if (difference > 0) { result = 1; } else { if (difference < 0) { result = -1; } else { result = 0; } } } // CASE 2 : Comparing to another TimePeriod object // ----------------------------------------------- else { RegularTimePeriod rtp = (RegularTimePeriod) obj; final long thisVal = this.getFirstMillisecond(); final long anotherVal = rtp.getFirstMillisecond(); result = (thisVal < anotherVal ? -1 : (thisVal == anotherVal ? 0 : 1)); } return result; } /** * Returns the first millisecond of the time period. * * @param calendar the calendar ({@code null} not permitted). * * @return The first millisecond of the time period. * * @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 day = this.day.getDayOfMonth(); calendar.clear(); calendar.set(year, month, day, this.hour, this.minute, this.second); calendar.set(Calendar.MILLISECOND, this.millisecond); return calendar.getTimeInMillis(); } /** * Returns the last millisecond of the time period. * * @param calendar the calendar (<code>null</code> not permitted). * * @return The last millisecond of the time period. * * @throws NullPointerException if {@code calendar} is {@code null}. */ @Override public long getLastMillisecond(Calendar calendar) { return getFirstMillisecond(calendar); } }