001 /* 002 * Copyright 2001-2007 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.field; 017 018 import org.joda.time.Chronology; 019 import org.joda.time.DateTimeField; 020 021 /** 022 * Converts a strict DateTimeField into a lenient one. By being lenient, the 023 * set method accepts out of bounds values, performing an addition instead. 024 * <p> 025 * LenientDateTimeField is thread-safe and immutable. 026 * 027 * @author Brian S O'Neill 028 * @see org.joda.time.chrono.LenientChronology 029 * @see StrictDateTimeField 030 * @since 1.0 031 */ 032 public class LenientDateTimeField extends DelegatedDateTimeField { 033 034 private static final long serialVersionUID = 8714085824173290599L; 035 036 private final Chronology iBase; 037 038 /** 039 * Returns a lenient version of the given field. If it is already lenient, 040 * then it is returned as-is. Otherwise, a new LenientDateTimeField is 041 * returned. 042 */ 043 public static DateTimeField getInstance(DateTimeField field, Chronology base) { 044 if (field == null) { 045 return null; 046 } 047 if (field instanceof StrictDateTimeField) { 048 field = ((StrictDateTimeField)field).getWrappedField(); 049 } 050 if (field.isLenient()) { 051 return field; 052 } 053 return new LenientDateTimeField(field, base); 054 } 055 056 protected LenientDateTimeField(DateTimeField field, Chronology base) { 057 super(field); 058 iBase = base; 059 } 060 061 public final boolean isLenient() { 062 return true; 063 } 064 065 /** 066 * Set values which may be out of bounds by adding the difference between 067 * the new value and the current value. 068 */ 069 public long set(long instant, int value) { 070 // lenient needs to handle time zone chronologies 071 // so we do the calculation using local milliseconds 072 long localInstant = iBase.getZone().convertUTCToLocal(instant); 073 long difference = FieldUtils.safeSubtract(value, get(instant)); 074 localInstant = getType().getField(iBase.withUTC()).add(localInstant, difference); 075 return iBase.getZone().convertLocalToUTC(localInstant, false, instant); 076 } 077 }