Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2013, 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.] * * ----------- * Second.java * ----------- * (C) Copyright 2001-2013, by Object Refinery Limited. * * Original Author: David Gilbert (for Object Refinery Limited); * Contributor(s): -; * * Changes * ------- * 11-Oct-2001 : Version 1 (DG); * 18-Dec-2001 : Changed order of parameters in constructor (DG); * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG); * 14-Feb-2002 : Fixed bug in Second(Date) constructor, and changed start of * range to zero from one (DG); * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to * evaluate with reference to a particular time zone (DG); * 13-Mar-2002 : Added parseSecond() method (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); * 05-Mar-2003 : Fixed bug in getLastMillisecond() picked up in JUnit * tests (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); * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE (DG); * 02-Mar-2009 : Added new constructor with Locale (DG); * 05-Jul-2012 : Replaced getTime().getTime() with getTimeInMillis() (DG); * 03-Jul-2013 : Use ParamChecks (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 second in a particular day. This class is immutable, which is * a requirement for all {@link RegularTimePeriod} subclasses. */ public class Second extends RegularTimePeriod implements Serializable { /** For serialization. */ private static final long serialVersionUID = -6536564190712383466L; /** Useful constant for the first second in a minute. */ public static final int FIRST_SECOND_IN_MINUTE = 0; /** Useful constant for the last second in a minute. */ public static final int LAST_SECOND_IN_MINUTE = 59; /** The day. */ private Day day; /** The hour of the day. */ private byte hour; /** The minute. */ private byte minute; /** The second. */ private byte second; /** * The first millisecond. We don't store the last millisecond, because it * is always firstMillisecond + 999L. */ private long firstMillisecond; /** * Constructs a new Second, based on the system date/time. */ public Second() { this(new Date()); } /** * Constructs a new Second. * * @param second the second (0 to 24*60*60-1). * @param minute the minute (<code>null</code> not permitted). */ public Second(int second, Minute minute) { ParamChecks.nullNotPermitted(minute, "minute"); this.day = minute.getDay(); this.hour = (byte) minute.getHourValue(); this.minute = (byte) minute.getMinute(); this.second = (byte) second; peg(Calendar.getInstance()); } /** * Creates a new second. * * @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 Second(int second, int minute, int hour, int day, int month, int year) { this(second, new Minute(minute, hour, day, month, year)); } /** * Constructs a new instance from the specified date/time and the default * time zone.. * * @param time the time (<code>null</code> not permitted). * * @see #Second(Date, TimeZone) */ public Second(Date time) { this(time, TimeZone.getDefault(), Locale.getDefault()); } /** * Creates a new second based on the supplied time and time zone. * * @param time the instant in time. * @param zone the time zone. * * @deprecated As of 1.0.13, use the constructor that specifies the locale * also. */ public Second(Date time, TimeZone zone) { this(time, zone, Locale.getDefault()); } /** * Creates a new second based on the supplied time and time zone. * * @param time the time (<code>null</code> not permitted). * @param zone the time zone (<code>null</code> not permitted). * @param locale the locale (<code>null</code> not permitted). * * @since 1.0.13 */ public Second(Date time, TimeZone zone, Locale locale) { Calendar calendar = Calendar.getInstance(zone, locale); calendar.setTime(time); 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 within the minute. * * @return The second (0 - 59). */ public int getSecond() { return this.second; } /** * Returns the minute. * * @return The minute (never <code>null</code>). */ public Minute getMinute() { return new Minute(this.minute, new Hour(this.hour, this.day)); } /** * 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 + 999L; } /** * 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 second preceding this one. * * @return The second preceding this one. */ @Override public RegularTimePeriod previous() { Second result = null; if (this.second != FIRST_SECOND_IN_MINUTE) { result = new Second(this.second - 1, getMinute()); } else { Minute previous = (Minute) getMinute().previous(); if (previous != null) { result = new Second(LAST_SECOND_IN_MINUTE, previous); } } return result; } /** * Returns the second following this one. * * @return The second following this one. */ @Override public RegularTimePeriod next() { Second result = null; if (this.second != LAST_SECOND_IN_MINUTE) { result = new Second(this.second + 1, getMinute()); } else { Minute next = (Minute) getMinute().next(); if (next != null) { result = new Second(FIRST_SECOND_IN_MINUTE, next); } } return result; } /** * Returns a serial index number for the minute. * * @return The serial index number. */ @Override public long getSerialIndex() { long hourIndex = this.day.getSerialIndex() * 24L + this.hour; long minuteIndex = hourIndex * 60L + this.minute; return minuteIndex * 60L + this.second; } /** * Returns the first millisecond of the minute. * * @param calendar the calendar/timezone (<code>null</code> not permitted). * * @return The first millisecond. * * @throws NullPointerException if <code>calendar</code> is * <code>null</code>. */ @Override public long getFirstMillisecond(Calendar calendar) { int year = this.day.getYear(); int month = this.day.getMonth() - 1; int d = this.day.getDayOfMonth(); calendar.clear(); calendar.set(year, month, d, this.hour, this.minute, this.second); calendar.set(Calendar.MILLISECOND, 0); return calendar.getTimeInMillis(); } /** * Returns the last millisecond of the second. * * @param calendar the calendar/timezone (<code>null</code> not permitted). * * @return The last millisecond. * * @throws NullPointerException if <code>calendar</code> is * <code>null</code>. */ @Override public long getLastMillisecond(Calendar calendar) { return getFirstMillisecond(calendar) + 999L; } /** * Tests the equality of this object against an arbitrary Object. * <P> * This method will return true ONLY if the object is a Second object * representing the same second as this instance. * * @param obj the object to compare (<code>null</code> permitted). * * @return <code>true</code> if second and minute of this and the object * are the same. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof Second)) { return false; } Second that = (Second) obj; 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 hash code. */ @Override public int hashCode() { int result = 17; result = 37 * result + this.second; result = 37 * result + this.minute; result = 37 * result + this.hour; result = 37 * result + this.day.hashCode(); return result; } /** * Returns an integer indicating the order of this Second 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 Second object // ------------------------------------------- if (o1 instanceof Second) { Second s = (Second) o1; if (this.firstMillisecond < s.firstMillisecond) { return -1; } else if (this.firstMillisecond > s.firstMillisecond) { return 1; } else { return 0; } } // 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 a new instance by parsing a string. The string is assumed to * be in the format "YYYY-MM-DD HH:MM:SS", perhaps with leading or trailing * whitespace. * * @param s the string to parse. * * @return The second, or <code>null</code> if the string is not parseable. */ public static Second parseSecond(String s) { Second result = null; s = s.trim(); String daystr = s.substring(0, Math.min(10, s.length())); Day day = Day.parseDay(daystr); if (day != null) { String hmsstr = s.substring(Math.min(daystr.length() + 1, s.length()), s.length()); hmsstr = hmsstr.trim(); int l = hmsstr.length(); String hourstr = hmsstr.substring(0, Math.min(2, l)); String minstr = hmsstr.substring(Math.min(3, l), Math.min(5, l)); String secstr = hmsstr.substring(Math.min(6, l), Math.min(8, l)); int hour = Integer.parseInt(hourstr); if ((hour >= 0) && (hour <= 23)) { int minute = Integer.parseInt(minstr); if ((minute >= 0) && (minute <= 59)) { Minute m = new Minute(minute, new Hour(hour, day)); int second = Integer.parseInt(secstr); if ((second >= 0) && (second <= 59)) { result = new Second(second, m); } } } } return result; } }