001    /*
002     * SonarQube, open source software quality management tool.
003     * Copyright (C) 2008-2014 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * SonarQube is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * SonarQube is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public License
017     * along with this program; if not, write to the Free Software Foundation,
018     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019     */
020    package org.sonar.api.utils;
021    
022    import javax.annotation.Nullable;
023    
024    import java.io.NotSerializableException;
025    import java.io.ObjectInputStream;
026    import java.io.ObjectOutputStream;
027    import java.lang.ref.Reference;
028    import java.lang.ref.SoftReference;
029    import java.text.DateFormat;
030    import java.text.FieldPosition;
031    import java.text.ParsePosition;
032    import java.text.SimpleDateFormat;
033    import java.util.Date;
034    
035    /**
036     * Parses and formats <a href="http://en.wikipedia.org/wiki/ISO_8601">ISO 8601</a> dates.
037     * This class is thread-safe.
038     *
039     * @since 2.7
040     */
041    public final class DateUtils {
042      public static final String DATE_FORMAT = "yyyy-MM-dd";
043      public static final String DATETIME_FORMAT = "yyyy-MM-dd'T'HH:mm:ssZ";
044    
045      private static final ThreadSafeDateFormat THREAD_SAFE_DATE_FORMAT = new ThreadSafeDateFormat(DATE_FORMAT);
046      private static final ThreadSafeDateFormat THREAD_SAFE_DATETIME_FORMAT = new ThreadSafeDateFormat(DATETIME_FORMAT);
047    
048      private DateUtils() {
049      }
050    
051      public static String formatDate(Date d) {
052        return THREAD_SAFE_DATE_FORMAT.format(d);
053      }
054    
055      public static String formatDateTime(Date d) {
056        return THREAD_SAFE_DATETIME_FORMAT.format(d);
057      }
058    
059      public static String formatDateTimeNullSafe(@Nullable Date date) {
060        if (date == null) {
061          return "";
062        }
063    
064        return THREAD_SAFE_DATETIME_FORMAT.format(date);
065      }
066    
067      /**
068       * @param s string in format {@link #DATE_FORMAT}
069       * @throws SonarException when string cannot be parsed
070       */
071      public static Date parseDate(String s) {
072        ParsePosition pos = new ParsePosition(0);
073        Date result = THREAD_SAFE_DATE_FORMAT.parse(s, pos);
074        if (pos.getIndex() != s.length()) {
075          throw new SonarException("The date '" + s + "' does not respect format '" + DATE_FORMAT + "'");
076        }
077        return result;
078      }
079    
080      /**
081       * Parse format {@link #DATE_FORMAT}. This method never throws exception.
082       *
083       * @param s any string
084       * @return the date, null if parsing error or null string
085       * @since 3.0
086       */
087      public static Date parseDateQuietly(@Nullable String s) {
088        Date date = null;
089        if (s != null) {
090          try {
091            date = parseDate(s);
092          } catch (RuntimeException e) {
093            // ignore
094          }
095    
096        }
097        return date;
098      }
099    
100      /**
101       * @param s string in format {@link #DATETIME_FORMAT}
102       * @throws SonarException when string cannot be parsed
103       */
104    
105      public static Date parseDateTime(String s) {
106        ParsePosition pos = new ParsePosition(0);
107        Date result = THREAD_SAFE_DATETIME_FORMAT.parse(s, pos);
108        if (pos.getIndex() != s.length()) {
109          throw new SonarException("The date '" + s + "' does not respect format '" + DATETIME_FORMAT + "'");
110        }
111        return result;
112      }
113    
114      /**
115       * Parse format {@link #DATETIME_FORMAT}. This method never throws exception.
116       *
117       * @param s any string
118       * @return the datetime, null if parsing error or null string
119       */
120      public static Date parseDateTimeQuietly(@Nullable String s) {
121        Date datetime = null;
122        if (s != null) {
123          try {
124            datetime = parseDateTime(s);
125          } catch (RuntimeException e) {
126            // ignore
127          }
128    
129        }
130        return datetime;
131      }
132    
133      public static Date addDays(Date date, int numberOfDays) {
134        return org.apache.commons.lang.time.DateUtils.addDays(date, numberOfDays);
135      }
136    
137      static class ThreadSafeDateFormat extends DateFormat {
138        private final String format;
139        private final ThreadLocal<Reference<DateFormat>> cache = new ThreadLocal<Reference<DateFormat>>() {
140          @Override
141          public Reference<DateFormat> get() {
142            Reference<DateFormat> softRef = super.get();
143            if (softRef == null || softRef.get() == null) {
144              softRef = new SoftReference<DateFormat>(new SimpleDateFormat(format));
145              super.set(softRef);
146            }
147            return softRef;
148          }
149        };
150    
151        ThreadSafeDateFormat(String format) {
152          this.format = format;
153        }
154    
155        private DateFormat getDateFormat() {
156          return (DateFormat) ((Reference) cache.get()).get();
157        }
158    
159        @Override
160        public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
161          return getDateFormat().format(date, toAppendTo, fieldPosition);
162        }
163    
164        @Override
165        public Date parse(String source, ParsePosition pos) {
166          return getDateFormat().parse(source, pos);
167        }
168    
169        private void readObject(ObjectInputStream ois) throws NotSerializableException {
170          throw new NotSerializableException();
171        }
172    
173        private void writeObject(ObjectOutputStream ois) throws NotSerializableException {
174          throw new NotSerializableException();
175        }
176      }
177    }