001    /*
002     *  Copyright 2001-2005 Stephen Colebourne
003     *
004     *  Licensed under the Apache License, Version 2.0 (the "License");
005     *  you may not use this file except in compliance with the License.
006     *  You may obtain a copy of the License at
007     *
008     *      http://www.apache.org/licenses/LICENSE-2.0
009     *
010     *  Unless required by applicable law or agreed to in writing, software
011     *  distributed under the License is distributed on an "AS IS" BASIS,
012     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     *  See the License for the specific language governing permissions and
014     *  limitations under the License.
015     */
016    package org.joda.time.base;
017    
018    import java.util.Calendar;
019    import java.util.GregorianCalendar;
020    import java.util.Locale;
021    
022    import org.joda.time.DateTimeFieldType;
023    import org.joda.time.DateTimeZone;
024    import org.joda.time.ReadableDateTime;
025    import org.joda.time.format.DateTimeFormat;
026    
027    /**
028     * AbstractDateTime provides the common behaviour for datetime classes.
029     * <p>
030     * This class should generally not be used directly by API users.
031     * The {@link ReadableDateTime} interface should be used when different 
032     * kinds of date/time objects are to be referenced.
033     * <p>
034     * Whenever you want to implement <code>ReadableDateTime</code> you should
035     * extend this class.
036     * <p>
037     * AbstractDateTime subclasses may be mutable and not thread-safe.
038     *
039     * @author Brian S O'Neill
040     * @author Stephen Colebourne
041     * @since 1.0
042     */
043    public abstract class AbstractDateTime
044            extends AbstractInstant
045            implements ReadableDateTime {
046    
047        /**
048         * Constructor.
049         */
050        protected AbstractDateTime() {
051            super();
052        }
053    
054        //-----------------------------------------------------------------------
055        /**
056         * Get the value of one of the fields of a datetime.
057         * <p>
058         * This method uses the chronology of the datetime to obtain the value.
059         * It is essentially a generic way of calling one of the get methods.
060         *
061         * @param type  a field type, usually obtained from DateTimeFieldType
062         * @return the value of that field
063         * @throws IllegalArgumentException if the field type is null
064         */
065        public int get(DateTimeFieldType type) {
066            if (type == null) {
067                throw new IllegalArgumentException("The DateTimeFieldType must not be null");
068            }
069            return type.getField(getChronology()).get(getMillis());
070        }
071    
072        //-----------------------------------------------------------------------
073        /**
074         * Get the era field value.
075         * 
076         * @return the era
077         */
078        public int getEra() {
079            return getChronology().era().get(getMillis());
080        }
081    
082        /**
083         * Get the year of era field value.
084         * 
085         * @return the year of era
086         */
087        public int getCenturyOfEra() {
088            return getChronology().centuryOfEra().get(getMillis());
089        }
090    
091        /**
092         * Get the year of era field value.
093         * 
094         * @return the year of era
095         */
096        public int getYearOfEra() {
097            return getChronology().yearOfEra().get(getMillis());
098        }
099    
100        /**
101         * Get the year of century field value.
102         * 
103         * @return the year of century
104         */
105        public int getYearOfCentury() {
106            return getChronology().yearOfCentury().get(getMillis());
107        }
108    
109        /**
110         * Get the year field value.
111         * 
112         * @return the year
113         */
114        public int getYear() {
115            return getChronology().year().get(getMillis());
116        }
117    
118        /**
119         * Get the weekyear field value.
120         * 
121         * @return the year of a week based year
122         */
123        public int getWeekyear() {
124            return getChronology().weekyear().get(getMillis());
125        }
126    
127        /**
128         * Get the month of year field value.
129         * 
130         * @return the month of year
131         */
132        public int getMonthOfYear() {
133            return getChronology().monthOfYear().get(getMillis());
134        }
135    
136        /**
137         * Get the week of weekyear field value.
138         * 
139         * @return the week of a week based year
140         */
141        public int getWeekOfWeekyear() {
142            return getChronology().weekOfWeekyear().get(getMillis());
143        }
144    
145        /**
146         * Get the day of year field value.
147         * 
148         * @return the day of year
149         */
150        public int getDayOfYear() {
151            return getChronology().dayOfYear().get(getMillis());
152        }
153    
154        /**
155         * Get the day of month field value.
156         * <p>
157         * The values for the day of month are defined in {@link org.joda.time.DateTimeConstants}.
158         * 
159         * @return the day of month
160         */
161        public int getDayOfMonth() {
162            return getChronology().dayOfMonth().get(getMillis());
163        }
164    
165        /**
166         * Get the day of week field value.
167         * <p>
168         * The values for the day of week are defined in {@link org.joda.time.DateTimeConstants}.
169         * 
170         * @return the day of week
171         */
172        public int getDayOfWeek() {
173            return getChronology().dayOfWeek().get(getMillis());
174        }
175    
176        //-----------------------------------------------------------------------
177        /**
178         * Get the hour of day field value.
179         *
180         * @return the hour of day
181         */
182        public int getHourOfDay() {
183            return getChronology().hourOfDay().get(getMillis());
184        }
185    
186        /**
187         * Get the minute of day field value.
188         *
189         * @return the minute of day
190         */
191        public int getMinuteOfDay() {
192            return getChronology().minuteOfDay().get(getMillis());
193        }
194    
195        /**
196         * Get the minute of hour field value.
197         *
198         * @return the minute of hour
199         */
200        public int getMinuteOfHour() {
201            return getChronology().minuteOfHour().get(getMillis());
202        }
203    
204        /**
205         * Get the second of day field value.
206         *
207         * @return the second of day
208         */
209        public int getSecondOfDay() {
210            return getChronology().secondOfDay().get(getMillis());
211        }
212    
213        /**
214         * Get the second of minute field value.
215         *
216         * @return the second of minute
217         */
218        public int getSecondOfMinute() {
219            return getChronology().secondOfMinute().get(getMillis());
220        }
221    
222        /**
223         * Get the millis of day field value.
224         *
225         * @return the millis of day
226         */
227        public int getMillisOfDay() {
228            return getChronology().millisOfDay().get(getMillis());
229        }
230    
231        /**
232         * Get the millis of second field value.
233         *
234         * @return the millis of second
235         */
236        public int getMillisOfSecond() {
237            return getChronology().millisOfSecond().get(getMillis());
238        }
239    
240        //-----------------------------------------------------------------------
241        /**
242         * Get the date time as a <code>java.util.Calendar</code>, assigning
243         * exactly the same millisecond instant.
244         * The locale is passed in, enabling Calendar to select the correct
245         * localized subclass.
246         * <p>
247         * The JDK and Joda-Time both have time zone implementations and these
248         * differ in accuracy. Joda-Time's implementation is generally more up to
249         * date and thus more accurate - for example JDK1.3 has no historical data.
250         * The effect of this is that the field values of the <code>Calendar</code>
251         * may differ from those of this object, even though the milliseond value
252         * is the same. Most of the time this just means that the JDK field values
253         * are wrong, as our time zone information is more up to date.
254         *
255         * @param locale  the locale to get the Calendar for, or default if null
256         * @return a localized Calendar initialised with this datetime
257         */
258        public Calendar toCalendar(Locale locale) {
259            if (locale == null) {
260                locale = Locale.getDefault();
261            }
262            DateTimeZone zone = getZone();
263            Calendar cal = Calendar.getInstance(zone.toTimeZone(), locale);
264            cal.setTime(toDate());
265            return cal;
266        }
267    
268        /**
269         * Get the date time as a <code>java.util.GregorianCalendar</code>,
270         * assigning exactly the same millisecond instant.
271         * <p>
272         * The JDK and Joda-Time both have time zone implementations and these
273         * differ in accuracy. Joda-Time's implementation is generally more up to
274         * date and thus more accurate - for example JDK1.3 has no historical data.
275         * The effect of this is that the field values of the <code>Calendar</code>
276         * may differ from those of this object, even though the milliseond value
277         * is the same. Most of the time this just means that the JDK field values
278         * are wrong, as our time zone information is more up to date.
279         *
280         * @return a GregorianCalendar initialised with this datetime
281         */
282        public GregorianCalendar toGregorianCalendar() {
283            DateTimeZone zone = getZone();
284            GregorianCalendar cal = new GregorianCalendar(zone.toTimeZone());
285            cal.setTime(toDate());
286            return cal;
287        }
288    
289        //-----------------------------------------------------------------------
290        /**
291         * Output the instant using the specified format pattern.
292         *
293         * @param pattern  the pattern specification, null means use <code>toString</code>
294         * @see  org.joda.time.format.DateTimeFormat
295         */
296        public String toString(String pattern) {
297            if (pattern == null) {
298                return toString();
299            }
300            return DateTimeFormat.forPattern(pattern).print(this);
301        }
302    
303        /**
304         * Output the instant using the specified format pattern.
305         *
306         * @param pattern  the pattern specification, null means use <code>toString</code>
307         * @param locale  Locale to use, null means default
308         * @see  org.joda.time.format.DateTimeFormat
309         */
310        public String toString(String pattern, Locale locale) throws IllegalArgumentException {
311            if (pattern == null) {
312                return toString();
313            }
314            return DateTimeFormat.forPattern(pattern).withLocale(locale).print(this);
315        }
316    
317    }