Java tutorial
/** * Copyright (C) 2010 MediaShelf <http://www.yourmediashelf.com/> * * This file is part of fedora-client. * * fedora-client 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 3 of the License, or * (at your option) any later version. * * fedora-client 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 fedora-client. If not, see <http://www.gnu.org/licenses/>. */ package com.yourmediashelf.fedora.util; import java.text.DecimalFormat; import java.util.Date; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.joda.time.DateTime; import org.joda.time.DateTimeZone; import org.joda.time.format.DateTimeFormatter; import org.joda.time.format.DateTimeFormatterBuilder; /** * Date and time utility methods. * * @author Edwin Shin */ public class DateUtility { /** * <p> * Regular expression string for the yearFrag: * </p> * <p> * a numeral consisting of at least four decimal digits, optionally preceded * by a minus sign; leading '0' digits are prohibited except to bring the * digit count up to four. * </p> */ private final static String yearFrag = "(-?([1-9][0-9]{3,}|0[0-9]{3}))"; /** * <p> * Regular expression string for the monthFrag: * </p> * <p> * a numeral consisting of exactly two decimal digits. * </p> */ private final static String monthFrag = "(0[1-9]|1[0-2])"; /** * <p> * Regular expression string for the dayFrag: * </p> * <p> * a numeral consisting of exactly two decimal digits. * </p> * <p> * Note that this regex does not enforce the day-of-month constraint, which * states: * </p> * <p> * The day value must be no more than 30 if month is one of 4, 6, 9, or 11; * no more than 28 if month is 2 and year is not divisible 4, or is * divisible by 100 but not by 400; and no more than 29 if month is 2 and * year is divisible by 400, or by 4 but not by 100. * </p> */ private final static String dayFrag = "(0[1-9]|[12][0-9]|3[01])"; /** * <p> * Regular expression string for the hourFrag: * </p> * <p> * a numeral consisting of exactly two decimal digits. * </p> */ private final static String hourFrag = "([01][0-9]|2[0-3])"; /** * <p> * Regular expression string for the minuteFrag: * </p> * <p> * a numeral consisting of exactly two decimal digits. * </p> */ private final static String minuteFrag = "([0-5][0-9])"; /** * <p> * Regular expression string for the secondFrag: * </p> * <p> * a numeral consisting of exactly two decimal digits, or two decimal * digits, a decimal point, and one or more trailing digits. * </p> */ private final static String secondFrag = "([0-5][0-9])(\\.([0-9]+))?"; /** * <p> * Regular expression string for the endOfDayFrag: * </p> * <p> * combines the {@link hourFrag}, {@link minuteFrag}, {@link minuteFrag}, * and their separators to represent midnight of the day, which is the first * moment of the next day. * </p> */ private final static String endOfDayFrag = String.format("(%s:%s:%s|(24:00:00(\\.0+)?))", hourFrag, minuteFrag, secondFrag); /** * <p> * Regular expression string for the timezoneFrag: * </p> * <p> * if present, specifies an offset between UTC and local time. Time zone * offsets are a count of minutes (expressed in timezoneFrag as a count of * hours and minutes) that are added or subtracted from UTC time to get the * "local" time. 'Z' is an alternative representation of the time zone * offset '00:00', which is, of course, zero minutes from UTC. * </p> */ private final static String timezoneFrag = "(Z|(\\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?"; /** * Concatenation of the {@link yearFrag}, {@link monthFrag}, {@link dayFrag} * , {@link endOfDayFrag}, {@link timezoneFrag}, and their separators. */ private final static String combined = String.format("%s-%s-%sT%s%s", yearFrag, monthFrag, dayFrag, endOfDayFrag, timezoneFrag); private final static Pattern XSD_DATETIME = Pattern.compile(combined); private final static ConcurrentMap<String, DateTimeFormatter> formatters = new ConcurrentHashMap<String, DateTimeFormatter>(); /** * Parses lexical representations of xsd:dateTimes, e.g. * "2010-01-31T14:21:03.001Z". Fractional seconds and timezone offset are * optional. * * <p>Note: fractional seconds are only supported to three digits of * precision.</p> * * @param input * an XML Schema 1.1 dateTime * @return a DateTime representing the input * @see "http://www.w3.org/TR/xmlschema11-2/#dateTime" */ public static DateTime parseXSDDateTime(String input) { Matcher m = XSD_DATETIME.matcher(input); if (!m.find()) { throw new IllegalArgumentException(input + " is not a valid XML Schema 1.1 dateTime."); } int year = Integer.parseInt(m.group(1)); int month = Integer.parseInt(m.group(3)); int day = Integer.parseInt(m.group(4)); int hour = 0, minute = 0, second = 0, millis = 0; boolean hasEndOfDayFrag = m.group(11) != null; if (!hasEndOfDayFrag) { hour = Integer.parseInt(m.group(6)); minute = Integer.parseInt(m.group(7)); second = Integer.parseInt(m.group(8)); // Parse fractional seconds // m.group(9), if not null/empty should be Strings such as ".5" or // ".050" which convert to 500 and 50, respectively. if (m.group(9) != null && !m.group(9).isEmpty()) { // parse as Double as a quick hack to drop trailing 0s. // e.g. ".0500" becomes 0.05 double d = Double.parseDouble(m.group(9)); // Something like the following would allow for int-sized // precision, but joda-time 1.6 only supports millis (i.e. <= 999). // see: org.joda.time.field.FieldUtils.verifyValueBounds // int digits = String.valueOf(d).length() - 2; // fractionalSeconds = (int) (d * Math.pow(10, digits)); millis = (int) (d * 1000); } } DateTimeZone zone = null; if (m.group(13) != null) { String tmp = m.group(13); if (tmp.equals("Z")) { tmp = "+00:00"; } zone = DateTimeZone.forID(tmp); } DateTime dt = new DateTime(year, month, day, hour, minute, second, millis, zone); if (hasEndOfDayFrag) { return dt.plusDays(1); } return dt; } /** * Convenience method that accepts a {@link java.util.Date}. * * @param date * @return An xsd:dateTime (in UTC) representation of date. * @see #getXSDFormatter(DateTime) */ public static String getXSDDateTime(Date date) { return getXSDDateTime(new DateTime(date)); } /** * Formats a {@link DateTime} as an xsd:dateTime in canonical form. * * <p>Note: fractional seconds are only supported to a maximum of three * digits.</p> * * @param dateTime * @return An xsd:dateTime (in UTC) representation of date. * @see "http://www.w3.org/TR/xmlschema11-2/#dateTime" */ public static String getXSDDateTime(DateTime dateTime) { return dateTime.withZone(DateTimeZone.UTC).toString(getXSDFormatter(dateTime)); } public static DateTimeFormatter getXSDFormatter(DateTime date) { int len = 0; int millis = date.getMillisOfSecond(); if (millis > 0) { // 0.050 becomes .05 (up to three digits, dropping trailing 0s) DecimalFormat df = new DecimalFormat(".###"); double d = millis / 1000.0; len = String.valueOf(df.format(d)).length() - 1; } return getXSDFormatter(len); } /** * Returns an xsd:dateTime formatter with the specified millisecond precision. * * @param millisLength number of digits of millisecond precision. Currently, * only 0-3 are valid arguments. * @return a formatter for yyyy-MM-dd'T'HH:mm:ss[.SSS]Z */ public static DateTimeFormatter getXSDFormatter(int millisLength) { String key = String.valueOf(millisLength); if (formatters.get(key) == null) { DateTimeFormatterBuilder bldr = new DateTimeFormatterBuilder().appendYear(4, 9).appendLiteral('-') .appendMonthOfYear(2).appendLiteral('-').appendDayOfMonth(2).appendLiteral('T') .appendHourOfDay(2).appendLiteral(':').appendMinuteOfHour(2).appendLiteral(':') .appendSecondOfMinute(2); if (millisLength > 0) { bldr = bldr.appendLiteral('.').appendFractionOfSecond(millisLength, millisLength); } bldr = bldr.appendTimeZoneOffset("Z", true, 2, 4); formatters.putIfAbsent(key, bldr.toFormatter()); } return formatters.get(key); } }