Ant example source code file (DateUtils.java)

This example Ant source code file (DateUtils.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

choiceformat, choiceformat, date, date, dateformat, hh:mm:ss, messageformat, minutes_format, parseexception, parseexception, seconds_format, simpledateformat, string, string, text, util

The DateUtils.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant.util;

import java.text.ChoiceFormat;
import java.text.DateFormat;
import java.text.MessageFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

/**
 * Helper methods to deal with date/time formatting with a specific
 * defined format (<a href="http://www.w3.org/TR/NOTE-datetime">ISO8601)
 * or a plurialization correct elapsed time in minutes and seconds.
 *
 * @since Ant 1.5
 *
 */
public final class DateUtils {

    /**
     * ISO8601-like pattern for date-time. It does not support timezone.
     *  <tt>yyyy-MM-ddTHH:mm:ss
     */
    public static final String ISO8601_DATETIME_PATTERN
            = "yyyy-MM-dd'T'HH:mm:ss";

    /**
     * ISO8601-like pattern for date. <tt>yyyy-MM-dd
     */
    public static final String ISO8601_DATE_PATTERN
            = "yyyy-MM-dd";

    /**
     * ISO8601-like pattern for time.  <tt>HH:mm:ss
     */
    public static final String ISO8601_TIME_PATTERN
            = "HH:mm:ss";

    /**
     * Format used for SMTP (and probably other) Date headers.
     */
    public static final DateFormat DATE_HEADER_FORMAT
        = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss ", Locale.US);


// code from Magesh moved from DefaultLogger and slightly modified
    private static final MessageFormat MINUTE_SECONDS
            = new MessageFormat("{0}{1}");

    private static final double[] LIMITS = {0, 1, 2};

    private static final String[] MINUTES_PART = {"", "1 minute ", "{0,number} minutes "};

    private static final String[] SECONDS_PART = {"0 seconds", "1 second", "{1,number} seconds"};

    private static final ChoiceFormat MINUTES_FORMAT =
            new ChoiceFormat(LIMITS, MINUTES_PART);

    private static final ChoiceFormat SECONDS_FORMAT =
            new ChoiceFormat(LIMITS, SECONDS_PART);

    static {
        MINUTE_SECONDS.setFormat(0, MINUTES_FORMAT);
        MINUTE_SECONDS.setFormat(1, SECONDS_FORMAT);
    }

    /** private constructor */
    private DateUtils() {
    }


    /**
     * Format a date/time into a specific pattern.
     * @param date the date to format expressed in milliseconds.
     * @param pattern the pattern to use to format the date.
     * @return the formatted date.
     */
    public static String format(long date, String pattern) {
        return format(new Date(date), pattern);
    }


    /**
     * Format a date/time into a specific pattern.
     * @param date the date to format expressed in milliseconds.
     * @param pattern the pattern to use to format the date.
     * @return the formatted date.
     */
    public static String format(Date date, String pattern) {
        DateFormat df = createDateFormat(pattern);
        return df.format(date);
    }


    /**
     * Format an elapsed time into a plurialization correct string.
     * It is limited only to report elapsed time in minutes and
     * seconds and has the following behavior.
     * <ul>
     * <li>minutes are not displayed when 0. (ie: "45 seconds")
     * <li>seconds are always displayed in plural form (ie "0 seconds" or
     * "10 seconds") except for 1 (ie "1 second")</li>
     * </ul>
     * @param millis the elapsed time to report in milliseconds.
     * @return the formatted text in minutes/seconds.
     */
    public static String formatElapsedTime(long millis) {
        long seconds = millis / 1000;
        long minutes = seconds / 60;
        Object[] args = {new Long(minutes), new Long(seconds % 60)};
        return MINUTE_SECONDS.format(args);
    }

    /**
     * return a lenient date format set to GMT time zone.
     * @param pattern the pattern used for date/time formatting.
     * @return the configured format for this pattern.
     */
    private static DateFormat createDateFormat(String pattern) {
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        TimeZone gmt = TimeZone.getTimeZone("GMT");
        sdf.setTimeZone(gmt);
        sdf.setLenient(true);
        return sdf;
    }

    /**
     * Calculate the phase of the moon for a given date.
     *
     * <p>Code heavily influenced by hacklib.c in 

     *
     * <p>The Algorithm:
     *
     * <pre>
     * moon period = 29.53058 days ~= 30, year = 365.2422 days
     *
     * days moon phase advances on first day of year compared to preceding year
     *  = 365.2422 - 12*29.53058 ~= 11
     *
     * years in Metonic cycle (time until same phases fall on the same days of
     *  the month) = 18.6 ~= 19
     *
     * moon phase on first day of year (epact) ~= (11*(year%19) + 18) % 30
     *  (18 as initial condition for 1900)
     *
     * current phase in days = first day phase + days elapsed in year
     *
     * 6 moons ~= 177 days
     * 177 ~= 8 reported phases * 22
     * + 11/22 for rounding
     * </pre>
     *
     * @param cal the calander.
     *
     * @return The phase of the moon as a number between 0 and 7 with
     *         0 meaning new moon and 4 meaning full moon.
     *
     * @since 1.2, Ant 1.5
     */
    public static int getPhaseOfMoon(Calendar cal) {
        int dayOfTheYear = cal.get(Calendar.DAY_OF_YEAR);
        int yearInMetonicCycle = ((cal.get(Calendar.YEAR) - 1900) % 19) + 1;
        int epact = (11 * yearInMetonicCycle + 18) % 30;
        if ((epact == 25 && yearInMetonicCycle > 11) || epact == 24) {
            epact++;
        }
        return (((((dayOfTheYear + epact) * 6) + 11) % 177) / 22) & 7;
    }

    /**
     * Returns the current Date in a format suitable for a SMTP date
     * header.
     * @return the current date.
     * @since Ant 1.5.2
     */
    public static String getDateForHeader() {
        Calendar cal = Calendar.getInstance();
        TimeZone tz = cal.getTimeZone();
        int offset = tz.getOffset(cal.get(Calendar.ERA),
                                  cal.get(Calendar.YEAR),
                                  cal.get(Calendar.MONTH),
                                  cal.get(Calendar.DAY_OF_MONTH),
                                  cal.get(Calendar.DAY_OF_WEEK),
                                  cal.get(Calendar.MILLISECOND));
        StringBuffer tzMarker = new StringBuffer(offset < 0 ? "-" : "+");
        offset = Math.abs(offset);
        int hours = offset / (60 * 60 * 1000);
        int minutes = offset / (60 * 1000) - 60 * hours;
        if (hours < 10) {
            tzMarker.append("0");
        }
        tzMarker.append(hours);
        if (minutes < 10) {
            tzMarker.append("0");
        }
        tzMarker.append(minutes);
        return DATE_HEADER_FORMAT.format(cal.getTime()) + tzMarker.toString();
    }

    /**
     * Parse a string as a datetime using the ISO8601_DATETIME format which is
     * <code>yyyy-MM-dd'T'HH:mm:ss
     *
     * @param datestr string to be parsed
     *
     * @return a java.util.Date object as parsed by the format.
     * @exception ParseException if the supplied string cannot be parsed by
     * this pattern.
     * @since Ant 1.6
     */
    public static Date parseIso8601DateTime(String datestr)
        throws ParseException {
        return new SimpleDateFormat(ISO8601_DATETIME_PATTERN).parse(datestr);
    }

    /**
     * Parse a string as a date using the ISO8601_DATE format which is
     * <code>yyyy-MM-dd
     *
     * @param datestr string to be parsed
     *
     * @return a java.util.Date object as parsed by the format.
     * @exception ParseException if the supplied string cannot be parsed by
     * this pattern.
     * @since Ant 1.6
     */
    public static Date parseIso8601Date(String datestr) throws ParseException {
        return new SimpleDateFormat(ISO8601_DATE_PATTERN).parse(datestr);
    }

    /**
     * Parse a string as a date using the either the ISO8601_DATETIME
     * or ISO8601_DATE formats.
     *
     * @param datestr string to be parsed
     *
     * @return a java.util.Date object as parsed by the formats.
     * @exception ParseException if the supplied string cannot be parsed by
     * either of these patterns.
     * @since Ant 1.6
     */
    public static Date parseIso8601DateTimeOrDate(String datestr)
        throws ParseException {
        try {
            return parseIso8601DateTime(datestr);
        } catch (ParseException px) {
            return parseIso8601Date(datestr);
        }
    }
}