001/*
002 * Copyright 2002-2018 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.joda;
018
019import java.util.Locale;
020
021import org.joda.time.format.DateTimeFormatter;
022
023import org.springframework.core.NamedThreadLocal;
024import org.springframework.lang.Nullable;
025
026/**
027 * A holder for a thread-local {@link JodaTimeContext}
028 * with user-specific Joda-Time settings.
029 *
030 * @author Keith Donald
031 * @author Juergen Hoeller
032 * @since 3.0
033 * @see org.springframework.context.i18n.LocaleContextHolder
034 */
035public final class JodaTimeContextHolder {
036
037        private static final ThreadLocal<JodaTimeContext> jodaTimeContextHolder =
038                        new NamedThreadLocal<>("JodaTimeContext");
039
040
041        private JodaTimeContextHolder() {
042        }
043
044
045        /**
046         * Reset the JodaTimeContext for the current thread.
047         */
048        public static void resetJodaTimeContext() {
049                jodaTimeContextHolder.remove();
050        }
051
052        /**
053         * Associate the given JodaTimeContext with the current thread.
054         * @param jodaTimeContext the current JodaTimeContext,
055         * or {@code null} to reset the thread-bound context
056         */
057        public static void setJodaTimeContext(@Nullable JodaTimeContext jodaTimeContext) {
058                if (jodaTimeContext == null) {
059                        resetJodaTimeContext();
060                }
061                else {
062                        jodaTimeContextHolder.set(jodaTimeContext);
063                }
064        }
065
066        /**
067         * Return the JodaTimeContext associated with the current thread, if any.
068         * @return the current JodaTimeContext, or {@code null} if none
069         */
070        @Nullable
071        public static JodaTimeContext getJodaTimeContext() {
072                return jodaTimeContextHolder.get();
073        }
074
075
076        /**
077         * Obtain a DateTimeFormatter with user-specific settings applied to the given base Formatter.
078         * @param formatter the base formatter that establishes default formatting rules
079         * (generally user independent)
080         * @param locale the current user locale (may be {@code null} if not known)
081         * @return the user-specific DateTimeFormatter
082         */
083        public static DateTimeFormatter getFormatter(DateTimeFormatter formatter, @Nullable Locale locale) {
084                DateTimeFormatter formatterToUse = (locale != null ? formatter.withLocale(locale) : formatter);
085                JodaTimeContext context = getJodaTimeContext();
086                return (context != null ? context.getFormatter(formatterToUse) : formatterToUse);
087        }
088
089}