001/*
002 * Copyright 2002-2017 the original author or authors.
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 *      https://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
017package org.springframework.format.datetime.standard;
018
019import java.time.ZoneId;
020import java.time.chrono.Chronology;
021import java.time.format.DateTimeFormatter;
022import java.util.TimeZone;
023
024import org.springframework.context.i18n.LocaleContext;
025import org.springframework.context.i18n.LocaleContextHolder;
026import org.springframework.context.i18n.TimeZoneAwareLocaleContext;
027import org.springframework.lang.Nullable;
028
029/**
030 * A context that holds user-specific <code>java.time</code> (JSR-310) settings
031 * such as the user's Chronology (calendar system) and time zone.
032 * A {@code null} property value indicate the user has not specified a setting.
033 *
034 * @author Juergen Hoeller
035 * @since 4.0
036 * @see DateTimeContextHolder
037 */
038public class DateTimeContext {
039
040        @Nullable
041        private Chronology chronology;
042
043        @Nullable
044        private ZoneId timeZone;
045
046
047        /**
048         * Set the user's chronology (calendar system).
049         */
050        public void setChronology(@Nullable Chronology chronology) {
051                this.chronology = chronology;
052        }
053
054        /**
055         * Return the user's chronology (calendar system), if any.
056         */
057        @Nullable
058        public Chronology getChronology() {
059                return this.chronology;
060        }
061
062        /**
063         * Set the user's time zone.
064         * <p>Alternatively, set a {@link TimeZoneAwareLocaleContext} on
065         * {@link LocaleContextHolder}. This context class will fall back to
066         * checking the locale context if no setting has been provided here.
067         * @see org.springframework.context.i18n.LocaleContextHolder#getTimeZone()
068         * @see org.springframework.context.i18n.LocaleContextHolder#setLocaleContext
069         */
070        public void setTimeZone(@Nullable ZoneId timeZone) {
071                this.timeZone = timeZone;
072        }
073
074        /**
075         * Return the user's time zone, if any.
076         */
077        @Nullable
078        public ZoneId getTimeZone() {
079                return this.timeZone;
080        }
081
082
083        /**
084         * Get the DateTimeFormatter with the this context's settings
085         * applied to the base {@code formatter}.
086         * @param formatter the base formatter that establishes default
087         * formatting rules, generally context-independent
088         * @return the contextual DateTimeFormatter
089         */
090        public DateTimeFormatter getFormatter(DateTimeFormatter formatter) {
091                if (this.chronology != null) {
092                        formatter = formatter.withChronology(this.chronology);
093                }
094                if (this.timeZone != null) {
095                        formatter = formatter.withZone(this.timeZone);
096                }
097                else {
098                        LocaleContext localeContext = LocaleContextHolder.getLocaleContext();
099                        if (localeContext instanceof TimeZoneAwareLocaleContext) {
100                                TimeZone timeZone = ((TimeZoneAwareLocaleContext) localeContext).getTimeZone();
101                                if (timeZone != null) {
102                                        formatter = formatter.withZone(timeZone.toZoneId());
103                                }
104                        }
105                }
106                return formatter;
107        }
108
109}