001 /*
002 * Copyright 2001-2013 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;
017
018 import org.joda.time.format.DateTimeFormat;
019
020 /**
021 * Exception thrown when attempting to create an instant or date-time that cannot exist.
022 * <p>
023 * Classes like {@code DateTime} only store valid date-times.
024 * One of the cases where validity is important is handling daylight savings time (DST).
025 * In many places DST is used, where the local clock moves forward by an hour in spring and back by an hour in autumn/fall.
026 * This means that in spring, there is a "gap" where a local time does not exist.
027 * <p>
028 * This exception refers to this gap, and it means that your application tried to create
029 * a date-time inside the gap - a time that did not exist.
030 * Since Joda-Time objects must be valid, this is not allowed.
031 * <p>
032 * Possible solutions may be as follows:<br />
033 * Use <code>LocalDateTime</code>, as all local date-times are valid.<br />
034 * When converting a <code>LocalDate</code> to a <code>DateTime</code>, then use <code>toDateTimeAsStartOfDay()</code>
035 * as this handles and manages any gaps.<br />
036 * When parsing, use <code>parseLocalDateTime()</code> if the string being parsed has no time-zone.
037 *
038 * @author Stephen Colebourne
039 * @since 2.2
040 */
041 public class IllegalInstantException extends IllegalArgumentException {
042
043 /** Serialization lock. */
044 private static final long serialVersionUID = 2858712538216L;
045
046
047 /**
048 * Constructor.
049 *
050 * @param message the message
051 */
052 public IllegalInstantException(String message) {
053 super(message);
054 }
055
056 /**
057 * Constructor.
058 *
059 * @param instantLocal the local instant
060 * @param zoneId the time-zone ID, may be null
061 */
062 public IllegalInstantException(long instantLocal, String zoneId) {
063 super(createMessage(instantLocal, zoneId));
064 }
065
066 private static String createMessage(long instantLocal, String zoneId) {
067 String localDateTime = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS").print(new Instant(instantLocal));
068 String zone = (zoneId != null ? " (" + zoneId + ")" : "");
069 return "Illegal instant due to time zone offset transition (daylight savings time 'gap'): " + localDateTime + zone;
070 }
071
072 //-----------------------------------------------------------------------
073 /**
074 * Checks if the exception is, or has a cause, of {@code IllegalInstantException}.
075 *
076 * @param ex the exception to check
077 * @return true if an {@code IllegalInstantException}
078 */
079 public static boolean isIllegalInstant(Throwable ex) {
080 if (ex instanceof IllegalInstantException) {
081 return true;
082 }
083 while (ex.getCause() != null && ex.getCause() != ex) {
084 return isIllegalInstant(ex.getCause());
085 }
086 return false;
087 }
088
089 }