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.] * * ------------ * Quarter.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); * 18-Dec-2001 : Changed order of parameters in constructor (DG); * 19-Dec-2001 : Added a new constructor as suggested by Paul English (DG); * 29-Jan-2002 : Added a new method parseQuarter(String) (DG); * 14-Feb-2002 : Fixed bug in Quarter(Date) constructor (DG); * 26-Feb-2002 : Changed getStart(), getMiddle() and getEnd() methods to * evaluate with reference to a particular time zone (DG); * 19-Mar-2002 : Changed API for TimePeriod classes (DG); * 24-Jun-2002 : Removed main method (just test code) (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); * 10-Dec-2005 : Fixed argument checking bug (1377239) in constructor (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); * 25-Nov-2008 : 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.date.MonthConstants; import org.jfree.chart.date.SerialDate; /** * Defines a quarter (in a given year). The range supported is Q1 1900 to * Q4 9999. This class is immutable, which is a requirement for all * {@link RegularTimePeriod} subclasses. */ public class Quarter extends RegularTimePeriod implements Serializable { /** For serialization. */ private static final long serialVersionUID = 3810061714380888671L; /** Constant for quarter 1. */ public static final int FIRST_QUARTER = 1; /** Constant for quarter 4. */ public static final int LAST_QUARTER = 4; /** The first month in each quarter. */ public static final int[] FIRST_MONTH_IN_QUARTER = { 0, MonthConstants.JANUARY, MonthConstants.APRIL, MonthConstants.JULY, MonthConstants.OCTOBER }; /** The last month in each quarter. */ public static final int[] LAST_MONTH_IN_QUARTER = { 0, MonthConstants.MARCH, MonthConstants.JUNE, MonthConstants.SEPTEMBER, MonthConstants.DECEMBER }; /** The year in which the quarter falls. */ private short year; /** The quarter (1-4). */ private byte quarter; /** The first millisecond. */ private long firstMillisecond; /** The last millisecond. */ private long lastMillisecond; /** * Constructs a new Quarter, based on the current system date/time. */ public Quarter() { this(new Date()); } /** * Constructs a new quarter. * * @param year the year (1900 to 9999). * @param quarter the quarter (1 to 4). */ public Quarter(int quarter, int year) { if ((quarter < FIRST_QUARTER) || (quarter > LAST_QUARTER)) { throw new IllegalArgumentException("Quarter outside valid range."); } this.year = (short) year; this.quarter = (byte) quarter; peg(Calendar.getInstance()); } /** * Constructs a new quarter. * * @param quarter the quarter (1 to 4). * @param year the year (1900 to 9999). */ public Quarter(int quarter, Year year) { if ((quarter < FIRST_QUARTER) || (quarter > LAST_QUARTER)) { throw new IllegalArgumentException("Quarter outside valid range."); } this.year = (short) year.getYear(); this.quarter = (byte) quarter; peg(Calendar.getInstance()); } /** * Constructs a new instance, based on a date/time and the default time * zone. * * @param time the date/time (<code>null</code> not permitted). * * @see #Quarter(Date, TimeZone, Locale) */ public Quarter(Date time) { this(time, TimeZone.getDefault(), Locale.getDefault()); } /** * Creates a new <code>Quarter</code> instance, using the specified * zone and locale. * * @param time the current time. * @param zone the time zone. * @param locale the locale. * * @since 1.0.12 */ public Quarter(Date time, TimeZone zone, Locale locale) { Calendar calendar = Calendar.getInstance(zone, locale); calendar.setTime(time); int month = calendar.get(Calendar.MONTH) + 1; this.quarter = (byte) SerialDate.monthCodeToQuarter(month); this.year = (short) calendar.get(Calendar.YEAR); peg(calendar); } /** * Returns the quarter. * * @return The quarter. */ public int getQuarter() { return this.quarter; } /** * Returns the year. * * @return The year. */ public Year getYear() { return new Year(this.year); } /** * Returns the year. * * @return The year. * * @since 1.0.3 */ public int getYearValue() { return this.year; } /** * Returns the first millisecond of the quarter. 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 quarter. * * @see #getLastMillisecond() */ @Override public long getFirstMillisecond() { return this.firstMillisecond; } /** * Returns the last millisecond of the quarter. 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 quarter. * * @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 quarter preceding this one. * * @return The quarter preceding this one (or <code>null</code> if this is * Q1 1900). */ @Override public RegularTimePeriod previous() { Quarter result; if (this.quarter > FIRST_QUARTER) { result = new Quarter(this.quarter - 1, this.year); } else { if (this.year > 1900) { result = new Quarter(LAST_QUARTER, this.year - 1); } else { result = null; } } return result; } /** * Returns the quarter following this one. * * @return The quarter following this one (or null if this is Q4 9999). */ @Override public RegularTimePeriod next() { Quarter result; if (this.quarter < LAST_QUARTER) { result = new Quarter(this.quarter + 1, this.year); } else { if (this.year < 9999) { result = new Quarter(FIRST_QUARTER, this.year + 1); } else { result = null; } } return result; } /** * Returns a serial index number for the quarter. * * @return The serial index number. */ @Override public long getSerialIndex() { return this.year * 4L + this.quarter; } /** * Tests the equality of this Quarter object to an arbitrary object. * Returns <code>true</code> if the target is a Quarter instance * representing the same quarter as this object. In all other cases, * returns <code>false</code>. * * @param obj the object (<code>null</code> permitted). * * @return <code>true</code> if quarter and year of this and the object are * the same. */ @Override public boolean equals(Object obj) { if (obj instanceof Quarter) { Quarter target = (Quarter) obj; return (this.quarter == target.getQuarter() && (this.year == target.getYearValue())); } return false; } /** * 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.quarter; result = 37 * result + this.year; return result; } /** * Returns an integer indicating the order of this Quarter 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(TimePeriod o1) { int result; // CASE 1 : Comparing to another Quarter object // -------------------------------------------- if (o1 instanceof Quarter) { Quarter q = (Quarter) o1; result = this.year - q.getYearValue(); if (result == 0) { result = this.quarter - q.getQuarter(); } } // CASE 2 : Comparing to another TimePeriod object // ----------------------------------------------- else { // more difficult case - evaluate later... result = 0; } return result; } /** * Returns a string representing the quarter (e.g. "Q1/2002"). * * @return A string representing the quarter. */ @Override public String toString() { return "Q" + this.quarter + "/" + this.year; } /** * Returns the first millisecond in the Quarter, evaluated using the * supplied calendar (which determines the time zone). * * @param calendar the calendar (<code>null</code> not permitted). * * @return The first millisecond in the Quarter. * * @throws NullPointerException if {@code calendar} is {@code null}. */ @Override public long getFirstMillisecond(Calendar calendar) { int month = Quarter.FIRST_MONTH_IN_QUARTER[this.quarter]; calendar.set(this.year, month - 1, 1, 0, 0, 0); calendar.set(Calendar.MILLISECOND, 0); return calendar.getTimeInMillis(); } /** * Returns the last millisecond of the Quarter, evaluated using the * supplied calendar (which determines the time zone). * * @param calendar the calendar (<code>null</code> not permitted). * * @return The last millisecond of the Quarter. * * @throws NullPointerException if {@code calendar} is {@code null}. */ @Override public long getLastMillisecond(Calendar calendar) { int month = Quarter.LAST_MONTH_IN_QUARTER[this.quarter]; int eom = SerialDate.lastDayOfMonth(month, this.year); calendar.set(this.year, month - 1, eom, 23, 59, 59); calendar.set(Calendar.MILLISECOND, 999); return calendar.getTimeInMillis(); } /** * Parses the string argument as a quarter. * <P> * This method should accept the following formats: "YYYY-QN" and "QN-YYYY", * where the "-" can be a space, a forward-slash (/), comma or a dash (-). * @param s A string representing the quarter. * * @return The quarter. */ public static Quarter parseQuarter(String s) { // find the Q and the integer following it (remove both from the // string)... int i = s.indexOf("Q"); if (i == -1) { throw new TimePeriodFormatException("Missing Q."); } if (i == s.length() - 1) { throw new TimePeriodFormatException("Q found at end of string."); } String qstr = s.substring(i + 1, i + 2); int quarter = Integer.parseInt(qstr); String remaining = s.substring(0, i) + s.substring(i + 2, s.length()); // replace any / , or - with a space remaining = remaining.replace('/', ' '); remaining = remaining.replace(',', ' '); remaining = remaining.replace('-', ' '); // parse the string... Year year = Year.parseYear(remaining.trim()); Quarter result = new Quarter(quarter, year); return result; } }