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.] * * ----------- * Minute.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 Minute(Date) constructor, and changed the range * to start from zero instead of 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 parseMinute() method (DG); * 19-Mar-2002 : Changed API, the minute is now defined in relation to an * Hour (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, and new constructor for * convenience (DG); * 30-Sep-2004 : Replaced getTime().getTime() with getTimeInMillis() (DG); * 04-Nov-2004 : Reverted change of 30-Sep-2004, because it won't work for * JDK 1.3 (DG); * ------------- JFREECHART 1.0.x --------------------------------------------- * 05-Oct-2006 : Updated API docs (DG); * 06-Oct-2006 : Refactored to cache first and last millisecond values (DG); * 11-Dec-2006 : Fix for previous() - bug 1611872 (DG); * 16-Sep-2008 : Deprecated DEFAULT_TIME_ZONE (DG); * 02-Mar-2009 : Added new constructor that specifies 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 minute. This class is immutable, which is a requirement for * all {@link RegularTimePeriod} subclasses. */ public class Minute extends RegularTimePeriod implements Serializable { /** For serialization. */ private static final long serialVersionUID = 2144572840034842871L; /** Useful constant for the first minute in a day. */ public static final int FIRST_MINUTE_IN_HOUR = 0; /** Useful constant for the last minute in a day. */ public static final int LAST_MINUTE_IN_HOUR = 59; /** The day. */ private Day day; /** The hour in which the minute falls. */ private byte hour; /** The minute. */ private byte minute; /** The first millisecond. */ private long firstMillisecond; /** The last millisecond. */ private long lastMillisecond; /** * Constructs a new Minute, based on the system date/time. */ public Minute() { this(new Date()); } /** * Constructs a new Minute. * * @param minute the minute (0 to 59). * @param hour the hour (<code>null</code> not permitted). */ public Minute(int minute, Hour hour) { ParamChecks.nullNotPermitted(hour, "hour"); this.minute = (byte) minute; this.hour = (byte) hour.getHour(); this.day = hour.getDay(); peg(Calendar.getInstance()); } /** * Constructs a new instance, based on the supplied date/time and * the default time zone. * * @param time the time (<code>null</code> not permitted). * * @see #Minute(Date, TimeZone) */ public Minute(Date time) { // defer argument checking this(time, TimeZone.getDefault(), Locale.getDefault()); } /** * Constructs a new Minute, based on the supplied date/time and timezone. * * @param time the time (<code>null</code> not permitted). * @param zone the time zone (<code>null</code> not permitted). * * @deprecated As of 1.0.13, use the constructor that specifies the locale * also. */ public Minute(Date time, TimeZone zone) { this(time, zone, Locale.getDefault()); } /** * Constructs a new Minute, based on the supplied date/time and timezone. * * @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 Minute(Date time, TimeZone zone, Locale locale) { ParamChecks.nullNotPermitted(time, "time"); ParamChecks.nullNotPermitted(zone, "zone"); ParamChecks.nullNotPermitted(locale, "locale"); Calendar calendar = Calendar.getInstance(zone, locale); calendar.setTime(time); int min = calendar.get(Calendar.MINUTE); this.minute = (byte) min; this.hour = (byte) calendar.get(Calendar.HOUR_OF_DAY); this.day = new Day(time, zone, locale); peg(calendar); } /** * Creates a new minute. * * @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 Minute(int minute, int hour, int day, int month, int year) { this(minute, new Hour(hour, new Day(day, month, year))); } /** * Returns the day. * * @return The day. * * @since 1.0.3 */ public Day getDay() { return this.day; } /** * Returns the hour. * * @return The hour (never <code>null</code>). */ public Hour getHour() { return new Hour(this.hour, this.day); } /** * Returns the hour. * * @return The hour. * * @since 1.0.3 */ public int getHourValue() { return this.hour; } /** * Returns the minute. * * @return The minute. */ public int getMinute() { return this.minute; } /** * Returns the first millisecond of the minute. 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 minute. * * @see #getLastMillisecond() */ @Override public long getFirstMillisecond() { return this.firstMillisecond; } /** * Returns the last millisecond of the minute. 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 minute. * * @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</code> not permitted). * * @since 1.0.3 */ @Override public void peg(Calendar calendar) { this.firstMillisecond = getFirstMillisecond(calendar); this.lastMillisecond = getLastMillisecond(calendar); } /** * Returns the minute preceding this one. * * @return The minute preceding this one. */ @Override public RegularTimePeriod previous() { Minute result; if (this.minute != FIRST_MINUTE_IN_HOUR) { result = new Minute(this.minute - 1, getHour()); } else { Hour h = (Hour) getHour().previous(); if (h != null) { result = new Minute(LAST_MINUTE_IN_HOUR, h); } else { result = null; } } return result; } /** * Returns the minute following this one. * * @return The minute following this one. */ @Override public RegularTimePeriod next() { Minute result; if (this.minute != LAST_MINUTE_IN_HOUR) { result = new Minute(this.minute + 1, getHour()); } else { // we are at the last minute in the hour... Hour nextHour = (Hour) getHour().next(); if (nextHour != null) { result = new Minute(FIRST_MINUTE_IN_HOUR, nextHour); } else { result = null; } } 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; return hourIndex * 60L + this.minute; } /** * Returns the first millisecond of the minute. * * @param calendar the calendar which defines the 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, 0); calendar.set(Calendar.MILLISECOND, 0); return calendar.getTimeInMillis(); } /** * Returns the last millisecond of the minute. * * @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) { 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, 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 a Minute object * representing the same minute as this instance. * * @param obj the object to compare (<code>null</code> permitted). * * @return <code>true</code> if the minute and hour value of this and the * object are the same. */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof Minute)) { return false; } Minute that = (Minute) obj; if (this.minute != that.minute) { return false; } if (this.hour != that.hour) { 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.minute; result = 37 * result + this.hour; result = 37 * result + this.day.hashCode(); return result; } /** * Returns an integer indicating the order of this Minute object relative * to the specified object: * * negative == before, zero == same, positive == after. * * @param o1 object to compare. * * @return negative == before, zero == same, positive == after. */ @Override public int compareTo(Object o1) { int result; // CASE 1 : Comparing to another Minute object // ------------------------------------------- if (o1 instanceof Minute) { Minute m = (Minute) o1; result = getHour().compareTo(m.getHour()); if (result == 0) { result = this.minute - m.getMinute(); } } // 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 Minute instance by parsing a string. The string is assumed to * be in the format "YYYY-MM-DD HH:MM", perhaps with leading or trailing * whitespace. * * @param s the minute string to parse. * * @return <code>null</code>, if the string is not parseable, the minute * otherwise. */ public static Minute parseMinute(String s) { Minute result = null; s = s.trim(); String daystr = s.substring(0, Math.min(10, s.length())); Day day = Day.parseDay(daystr); if (day != null) { String hmstr = s.substring(Math.min(daystr.length() + 1, s.length()), s.length()); hmstr = hmstr.trim(); String hourstr = hmstr.substring(0, Math.min(2, hmstr.length())); int hour = Integer.parseInt(hourstr); if ((hour >= 0) && (hour <= 23)) { String minstr = hmstr.substring(Math.min(hourstr.length() + 1, hmstr.length()), hmstr.length()); int minute = Integer.parseInt(minstr); if ((minute >= 0) && (minute <= 59)) { result = new Minute(minute, new Hour(hour, day)); } } } return result; } }