1 /*
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file:
31 *
32 * Copyright (c) 2011-2012, Stephen Colebourne & Michael Nascimento Santos
33 *
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions are met:
38 *
39 * * Redistributions of source code must retain the above copyright notice,
40 * this list of conditions and the following disclaimer.
41 *
42 * * Redistributions in binary form must reproduce the above copyright notice,
43 * this list of conditions and the following disclaimer in the documentation
44 * and/or other materials provided with the distribution.
45 *
46 * * Neither the name of JSR-310 nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
54 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
55 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
56 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
57 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
58 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
59 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
60 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 package java.time.format;
63
64 import static java.time.temporal.ChronoField.EPOCH_DAY;
65 import static java.time.temporal.ChronoField.INSTANT_SECONDS;
66 import static java.time.temporal.ChronoField.OFFSET_SECONDS;
67
68 import java.time.DateTimeException;
69 import java.time.Instant;
70 import java.time.ZoneId;
71 import java.time.ZoneOffset;
72 import java.time.chrono.ChronoLocalDate;
73 import java.time.chrono.Chronology;
74 import java.time.chrono.IsoChronology;
75 import java.time.temporal.ChronoField;
76 import java.time.temporal.TemporalAccessor;
77 import java.time.temporal.TemporalField;
78 import java.time.temporal.TemporalQuery;
79 import java.time.temporal.ValueRange;
80 import java.util.Locale;
81 import java.util.Objects;
82
83 /**
84 * Context object used during date and time printing.
85 * <p>
86 * This class provides a single wrapper to items used in the format.
87 *
88 * <h3>Specification for implementors</h3>
89 * This class is a mutable context intended for use from a single thread.
90 * Usage of the class is thread-safe within standard printing as the framework creates
91 * a new instance of the class for each format and printing is single-threaded.
92 *
93 * @since 1.8
94 */
95 final class DateTimePrintContext {
96
97 /**
98 * The temporal being output.
99 */
100 private TemporalAccessor temporal;
101 /**
102 * The formatter, not null.
103 */
104 private DateTimeFormatter formatter;
105 /**
106 * Whether the current formatter is optional.
107 */
108 private int optional;
109
110 /**
111 * Creates a new instance of the context.
112 *
113 * @param temporal the temporal object being output, not null
114 * @param formatter the formatter controlling the format, not null
115 */
116 DateTimePrintContext(TemporalAccessor temporal, DateTimeFormatter formatter) {
117 super();
118 this.temporal = adjust(temporal, formatter);
119 this.formatter = formatter;
120 }
121
122 private static TemporalAccessor adjust(final TemporalAccessor temporal, DateTimeFormatter formatter) {
123 // normal case first (early return is an optimization)
124 Chronology overrideChrono = formatter.getChronology();
125 ZoneId overrideZone = formatter.getZone();
126 if (overrideChrono == null && overrideZone == null) {
127 return temporal;
128 }
129
130 // ensure minimal change (early return is an optimization)
131 Chronology temporalChrono = temporal.query(TemporalQuery.chronology());
132 ZoneId temporalZone = temporal.query(TemporalQuery.zoneId());
133 if (Objects.equals(overrideChrono, temporalChrono)) {
134 overrideChrono = null;
135 }
136 if (Objects.equals(overrideZone, temporalZone)) {
137 overrideZone = null;
138 }
139 if (overrideChrono == null && overrideZone == null) {
140 return temporal;
141 }
142
143 // make adjustment
144 final Chronology effectiveChrono = (overrideChrono != null ? overrideChrono : temporalChrono);
145 if (overrideZone != null) {
146 // if have zone and instant, calculation is simple, defaulting chrono if necessary
147 if (temporal.isSupported(INSTANT_SECONDS)) {
148 Chronology chrono = (effectiveChrono != null ? effectiveChrono : IsoChronology.INSTANCE);
149 return chrono.zonedDateTime(Instant.from(temporal), overrideZone);
150 }
151 // block changing zone on OffsetTime, and similar problem cases
152 if (overrideZone.normalized() instanceof ZoneOffset && temporal.isSupported(OFFSET_SECONDS) &&
153 temporal.get(OFFSET_SECONDS) != overrideZone.getRules().getOffset(Instant.EPOCH).getTotalSeconds()) {
154 throw new DateTimeException("Unable to apply override zone '" + overrideZone +
155 "' because the temporal object being formatted has a different offset but" +
156 " does not represent an instant: " + temporal);
157 }
158 }
159 final ZoneId effectiveZone = (overrideZone != null ? overrideZone : temporalZone);
160 final ChronoLocalDate<?> effectiveDate;
161 if (overrideChrono != null) {
162 if (temporal.isSupported(EPOCH_DAY)) {
163 effectiveDate = effectiveChrono.date(temporal);
164 } else {
165 // check for date fields other than epoch-day, ignoring case of converting null to ISO
166 if (!(overrideChrono == IsoChronology.INSTANCE && temporalChrono == null)) {
167 for (ChronoField f : ChronoField.values()) {
168 if (f.isDateBased() && temporal.isSupported(f)) {
169 throw new DateTimeException("Unable to apply override chronology '" + overrideChrono +
170 "' because the temporal object being formatted contains date fields but" +
171 " does not represent a whole date: " + temporal);
172 }
173 }
174 }
175 effectiveDate = null;
176 }
177 } else {
178 effectiveDate = null;
179 }
180
181 // combine available data
182 // this is a non-standard temporal that is almost a pure delegate
183 // this better handles map-like underlying temporal instances
184 return new TemporalAccessor() {
185 @Override
186 public boolean isSupported(TemporalField field) {
187 if (effectiveDate != null && field.isDateBased()) {
188 return effectiveDate.isSupported(field);
189 }
190 return temporal.isSupported(field);
191 }
192 @Override
193 public ValueRange range(TemporalField field) {
194 if (effectiveDate != null && field.isDateBased()) {
195 return effectiveDate.range(field);
196 }
197 return temporal.range(field);
198 }
199 @Override
200 public long getLong(TemporalField field) {
201 if (effectiveDate != null && field.isDateBased()) {
202 return effectiveDate.getLong(field);
203 }
204 return temporal.getLong(field);
205 }
206 @SuppressWarnings("unchecked")
207 @Override
208 public <R> R query(TemporalQuery<R> query) {
209 if (query == TemporalQuery.chronology()) {
210 return (R) effectiveChrono;
211 }
212 if (query == TemporalQuery.zoneId()) {
213 return (R) effectiveZone;
214 }
215 if (query == TemporalQuery.precision()) {
216 return temporal.query(query);
217 }
218 return query.queryFrom(this);
219 }
220 };
221 }
222
223 //-----------------------------------------------------------------------
224 /**
225 * Gets the temporal object being output.
226 *
227 * @return the temporal object, not null
228 */
229 TemporalAccessor getTemporal() {
230 return temporal;
231 }
232
233 /**
234 * Gets the locale.
235 * <p>
236 * This locale is used to control localization in the format output except
237 * where localization is controlled by the symbols.
238 *
239 * @return the locale, not null
240 */
241 Locale getLocale() {
242 return formatter.getLocale();
243 }
244
245 /**
246 * Gets the formatting symbols.
247 * <p>
248 * The symbols control the localization of numeric output.
249 *
250 * @return the formatting symbols, not null
251 */
252 DateTimeFormatSymbols getSymbols() {
253 return formatter.getSymbols();
254 }
255
256 //-----------------------------------------------------------------------
257 /**
258 * Starts the printing of an optional segment of the input.
259 */
260 void startOptional() {
261 this.optional++;
262 }
263
264 /**
265 * Ends the printing of an optional segment of the input.
266 */
267 void endOptional() {
268 this.optional--;
269 }
270
271 /**
272 * Gets a value using a query.
273 *
274 * @param query the query to use, not null
275 * @return the result, null if not found and optional is true
276 * @throws DateTimeException if the type is not available and the section is not optional
277 */
278 <R> R getValue(TemporalQuery<R> query) {
279 R result = temporal.query(query);
280 if (result == null && optional == 0) {
281 throw new DateTimeException("Unable to extract value: " + temporal.getClass());
282 }
283 return result;
284 }
285
286 /**
287 * Gets the value of the specified field.
288 * <p>
289 * This will return the value for the specified field.
290 *
291 * @param field the field to find, not null
292 * @return the value, null if not found and optional is true
293 * @throws DateTimeException if the field is not available and the section is not optional
294 */
295 Long getValue(TemporalField field) {
296 try {
297 return temporal.getLong(field);
298 } catch (DateTimeException ex) {
299 if (optional > 0) {
300 return null;
301 }
302 throw ex;
303 }
304 }
305
306 //-----------------------------------------------------------------------
307 /**
308 * Returns a string version of the context for debugging.
309 *
310 * @return a string representation of the context, not null
311 */
312 @Override
313 public String toString() {
314 return temporal.toString();
315 }
316
317 }