testhssfdateutil.java

介绍java核心技术的pio编程方法以及基本概念

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package org.apache.poi.hssf.usermodel;

import junit.framework.TestCase;

import java.io.FileInputStream;
import java.util.Date;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;

import org.apache.poi.hssf.model.Workbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;

/**
 * Class TestHSSFDateUtil
 *
 *
 * @author  Dan Sherman (dsherman at isisph.com)
 * @author  Hack Kampbjorn (hak at 2mba.dk)
 * @author  Pavel Krupets (pkrupets at palmtreebusiness dot com)
 * @author Alex Jacoby (ajacoby at gmail.com)
 * @version %I%, %G%
 */

public class TestHSSFDateUtil
        extends TestCase
{

	public static final int CALENDAR_JANUARY = 0;
	public static final int CALENDAR_FEBRUARY = 1;
	public static final int CALENDAR_MARCH = 2;
	public static final int CALENDAR_APRIL = 3;
	public static final int CALENDAR_JULY = 6;
    public static final int CALENDAR_OCTOBER = 9;
    
    public TestHSSFDateUtil(String s)
    {
        super(s);
    }

    /**
     * Checks the date conversion functions in the HSSFDateUtil class.
     */

    public void testDateConversion()
            throws Exception
    {

        // Iteratating over the hours exposes any rounding issues.
        for (int hour = 0; hour < 23; hour++)
        {
            GregorianCalendar date      = new GregorianCalendar(2002, 0, 1,
                    hour, 1, 1);
            double            excelDate =
                    HSSFDateUtil.getExcelDate(date.getTime(), false);

            assertEquals("Checking hour = " + hour, date.getTime().getTime(),
                    HSSFDateUtil.getJavaDate(excelDate, false).getTime());
        }

        // check 1900 and 1904 date windowing conversions
        double excelDate = 36526.0;
        // with 1900 windowing, excelDate is Jan. 1, 2000
        // with 1904 windowing, excelDate is Jan. 2, 2004
        GregorianCalendar cal = new GregorianCalendar(2000,0,1); // Jan. 1, 2000
        Date dateIf1900 = cal.getTime();
        cal.add(GregorianCalendar.YEAR,4); // now Jan. 1, 2004
        cal.add(GregorianCalendar.DATE,1); // now Jan. 2, 2004
        Date dateIf1904 = cal.getTime();
        // 1900 windowing
        assertEquals("Checking 1900 Date Windowing",
                dateIf1900.getTime(),
                HSSFDateUtil.getJavaDate(excelDate,false).getTime());
        // 1904 windowing
        assertEquals("Checking 1904 Date Windowing",
                dateIf1904.getTime(),
                HSSFDateUtil.getJavaDate(excelDate,true).getTime());
    }

    /**
     * Checks the conversion of a java.util.date to Excel on a day when
     * Daylight Saving Time starts.
     */
    public void testExcelConversionOnDSTStart() {
        TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
        TimeZone.setDefault(cet);
        Calendar cal = new GregorianCalendar(2004, CALENDAR_MARCH, 28);
        for (int hour = 0; hour < 24; hour++) {

            // Skip 02:00 CET as that is the Daylight change time
            // and Java converts it automatically to 03:00 CEST
            if (hour == 2) {
                continue;
            }

            cal.set(Calendar.HOUR_OF_DAY, hour);
            Date javaDate = cal.getTime();
            double excelDate = HSSFDateUtil.getExcelDate(javaDate, false);
            double difference = excelDate - Math.floor(excelDate);
            int differenceInHours = (int) (difference * 24 * 60 + 0.5) / 60;
            assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
                    hour,
                    differenceInHours);
            assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
                    javaDate.getTime(),
                    HSSFDateUtil.getJavaDate(excelDate, false).getTime());
        }
    }

    /**
     * Checks the conversion of an Excel date to a java.util.date on a day when
     * Daylight Saving Time starts.
     */
    public void testJavaConversionOnDSTStart() {
        TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
        TimeZone.setDefault(cet);
        Calendar cal = new GregorianCalendar(2004, CALENDAR_MARCH, 28);
        double excelDate = HSSFDateUtil.getExcelDate(cal.getTime(), false);
        double oneHour = 1.0 / 24;
        double oneMinute = oneHour / 60;
        for (int hour = 0; hour < 24; hour++, excelDate += oneHour) {

            // Skip 02:00 CET as that is the Daylight change time
            // and Java converts it automatically to 03:00 CEST            
            if (hour == 2) {
                continue;
            }

            cal.set(Calendar.HOUR_OF_DAY, hour);
            Date javaDate = HSSFDateUtil.getJavaDate(excelDate, false);
            assertEquals("Checking " + hour + " hours on Daylight Saving Time start date",
                    excelDate,
                    HSSFDateUtil.getExcelDate(javaDate, false), oneMinute);
        }
    }

    /**
     * Checks the conversion of a java.util.Date to Excel on a day when
     * Daylight Saving Time ends.
     */
    public void testExcelConversionOnDSTEnd() {
        TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
        TimeZone.setDefault(cet);
        Calendar cal = new GregorianCalendar(2004, CALENDAR_OCTOBER, 31);
        for (int hour = 0; hour < 24; hour++) {
            cal.set(Calendar.HOUR_OF_DAY, hour);
            Date javaDate = cal.getTime();
            double excelDate = HSSFDateUtil.getExcelDate(javaDate, false);
            double difference = excelDate - Math.floor(excelDate);
            int differenceInHours = (int) (difference * 24 * 60 + 0.5) / 60;
            assertEquals("Checking " + hour + " hour on Daylight Saving Time end date",
                    hour,
                    differenceInHours);
            assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
                    javaDate.getTime(),
                    HSSFDateUtil.getJavaDate(excelDate, false).getTime());
        }
    }

    /**
     * Checks the conversion of an Excel date to java.util.Date on a day when
     * Daylight Saving Time ends.
     */
    public void testJavaConversionOnDSTEnd() {
        TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
        TimeZone.setDefault(cet);
        Calendar cal = new GregorianCalendar(2004, CALENDAR_OCTOBER, 31);
        double excelDate = HSSFDateUtil.getExcelDate(cal.getTime(), false);
        double oneHour = 1.0 / 24;
        double oneMinute = oneHour / 60;
        for (int hour = 0; hour < 24; hour++, excelDate += oneHour) {