001    /*
002     *  Copyright (C) 2008 Petr Nejedly <P.Nejedly@sh.cvut.cz>
003     *
004     *  This program is free software; you can redistribute it and/or modify
005     *  it under the terms of the GNU General Public License as published by
006     *  the Free Software Foundation; either version 2 of the License, or
007     *  (at your option) any later version.
008     *
009     *  This program is distributed in the hope that it will be useful,
010     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
011     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
012     *  GNU General Public License for more details.
013    
014     *  You should have received a copy of the GNU General Public License along
015     *  with this program; if not, write to the Free Software Foundation, Inc.,
016     *  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
017     */
018    
019    package org.openstreetmap.josm.tools;
020    
021    import java.text.ParsePosition;
022    import java.text.SimpleDateFormat;
023    import java.util.Calendar;
024    import java.util.Date;
025    import java.util.GregorianCalendar;
026    import java.util.TimeZone;
027    
028    import javax.xml.datatype.DatatypeConfigurationException;
029    import javax.xml.datatype.DatatypeFactory;
030    import javax.xml.datatype.XMLGregorianCalendar;
031    
032    /**
033     * A static utility class dealing with parsing XML date quickly and formatting
034     * a date to the XML UTC format regardless of current locale.
035     *
036     * @author nenik
037     */
038    public final class DateUtils {
039        private DateUtils() {}
040        /**
041         * A shared instance used for conversion between individual date fields
042         * and long millis time. It is guarded against conflict by the class lock.
043         * The shared instance is used because the construction, together
044         * with the timezone lookup, is very expensive.
045         */
046        private static GregorianCalendar calendar = new GregorianCalendar(TimeZone.getTimeZone("UTC"));
047        private static final DatatypeFactory XML_DATE;
048    
049        static {
050            calendar.setTimeInMillis(0);
051    
052            DatatypeFactory fact = null;
053            try {
054                fact = DatatypeFactory.newInstance();
055            } catch(DatatypeConfigurationException ce) {
056                ce.printStackTrace();
057            }
058            XML_DATE = fact;
059        }
060    
061        public static synchronized Date fromString(String str) {
062            // "2007-07-25T09:26:24{Z|{+|-}01:00}"
063            if (checkLayout(str, "xxxx-xx-xxTxx:xx:xxZ") ||
064                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx") ||
065                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx+xx:00") ||
066                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx-xx:00")) {
067                calendar.set(
068                    parsePart(str, 0, 4),
069                    parsePart(str, 5, 2)-1,
070                    parsePart(str, 8, 2),
071                    parsePart(str, 11, 2),
072                    parsePart(str, 14,2),
073                    parsePart(str, 17, 2));
074    
075                if (str.length() == 25) {
076                    int plusHr = parsePart(str, 20, 2);
077                    int mul = str.charAt(19) == '+' ? -3600000 : 3600000;
078                    calendar.setTimeInMillis(calendar.getTimeInMillis()+plusHr*mul);
079                }
080    
081                return calendar.getTime();
082            }
083            else if(checkLayout(str, "xxxx-xx-xxTxx:xx:xx.xxxZ") ||
084                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx.xxx") ||
085                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx.xxx+xx:00") ||
086                    checkLayout(str, "xxxx-xx-xxTxx:xx:xx.xxx-xx:00")) {
087                calendar.set(
088                    parsePart(str, 0, 4),
089                    parsePart(str, 5, 2)-1,
090                    parsePart(str, 8, 2),
091                    parsePart(str, 11, 2),
092                    parsePart(str, 14,2),
093                    parsePart(str, 17, 2));
094                long millis = parsePart(str, 20, 3);
095                if (str.length() == 29)
096                    millis += parsePart(str, 24, 2) * (str.charAt(23) == '+' ? -3600000 : 3600000);
097                calendar.setTimeInMillis(calendar.getTimeInMillis()+millis);
098    
099                return calendar.getTime();
100            }
101            else
102            {
103                // example date format "18-AUG-08 13:33:03"
104                SimpleDateFormat f = new SimpleDateFormat("dd-MMM-yy HH:mm:ss");
105                Date d = f.parse(str, new ParsePosition(0));
106                if(d != null)
107                    return d;
108            }
109    
110            try {
111                return XML_DATE.newXMLGregorianCalendar(str).toGregorianCalendar().getTime();
112            } catch (Exception ex) {
113                return new Date();
114            }
115        }
116    
117        public static synchronized String fromDate(Date date) {
118            calendar.setTime(date);
119            XMLGregorianCalendar xgc = XML_DATE.newXMLGregorianCalendar(calendar);
120            if (calendar.get(Calendar.MILLISECOND) == 0) xgc.setFractionalSecond(null);
121            return xgc.toXMLFormat();
122        }
123    
124        private static boolean checkLayout(String text, String pattern) {
125            if (text.length() != pattern.length()) return false;
126            for (int i=0; i<pattern.length(); i++) {
127                char pc = pattern.charAt(i);
128                char tc = text.charAt(i);
129                if(pc == 'x' && tc >= '0' && tc <= '9') continue;
130                else if(pc == 'x' || pc != tc) return false;
131            }
132            return true;
133        }
134    
135        private static int parsePart(String str, int off, int len) {
136            return Integer.valueOf(str.substring(off, off+len));
137        }
138    
139    }