Java tutorial
/* * Copyright 2001-2013 Stephen Colebourne * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.joda.time.field; import org.joda.time.DateTimeField; import org.joda.time.DateTimeFieldType; import org.joda.time.DurationField; /** * Generic offset adjusting datetime field. * <p> * OffsetDateTimeField is thread-safe and immutable. * * @author Brian S O'Neill * @since 1.0 */ public class OffsetDateTimeField extends DecoratedDateTimeField { @SuppressWarnings("unused") private static final long serialVersionUID = 3145790132623583142L; private final int iOffset; private final int iMin; private final int iMax; /** * Constructor. * * @param field the field to wrap, like "year()". * @param offset offset to add to field values * @throws IllegalArgumentException if offset is zero */ public OffsetDateTimeField(DateTimeField field, int offset) { this(field, (field == null ? null : field.getType()), offset, Integer.MIN_VALUE, Integer.MAX_VALUE); } /** * Constructor. * * @param field the field to wrap, like "year()". * @param type the field type this field actually uses * @param offset offset to add to field values * @throws IllegalArgumentException if offset is zero */ public OffsetDateTimeField(DateTimeField field, DateTimeFieldType type, int offset) { this(field, type, offset, Integer.MIN_VALUE, Integer.MAX_VALUE); } /** * Constructor. * * @param field the field to wrap, like "year()". * @param type the field type this field actually uses * @param offset offset to add to field values * @param minValue minimum allowed value * @param maxValue maximum allowed value * @throws IllegalArgumentException if offset is zero */ public OffsetDateTimeField(DateTimeField field, DateTimeFieldType type, int offset, int minValue, int maxValue) { super(field, type); if (offset == 0) { throw new IllegalArgumentException("The offset cannot be zero"); } iOffset = offset; if (minValue < (field.getMinimumValue() + offset)) { iMin = field.getMinimumValue() + offset; } else { iMin = minValue; } if (maxValue > (field.getMaximumValue() + offset)) { iMax = field.getMaximumValue() + offset; } else { iMax = maxValue; } } /** * Get the amount of offset units from the specified time instant. * * @param instant the time instant in millis to query. * @return the amount of units extracted from the input. */ public int get(long instant) { return super.get(instant) + iOffset; } /** * Add the specified amount of offset units to the specified time * instant. The amount added may be negative. * * @param instant the time instant in millis to update. * @param amount the amount of units to add (can be negative). * @return the updated time instant. */ public long add(long instant, int amount) { instant = super.add(instant, amount); FieldUtils.verifyValueBounds(this, get(instant), iMin, iMax); return instant; } /** * Add the specified amount of offset units to the specified time * instant. The amount added may be negative. * * @param instant the time instant in millis to update. * @param amount the amount of units to add (can be negative). * @return the updated time instant. */ public long add(long instant, long amount) { instant = super.add(instant, amount); FieldUtils.verifyValueBounds(this, get(instant), iMin, iMax); return instant; } /** * Add to the offset component of the specified time instant, * wrapping around within that component if necessary. * * @param instant the time instant in millis to update. * @param amount the amount of units to add (can be negative). * @return the updated time instant. */ public long addWrapField(long instant, int amount) { return set(instant, FieldUtils.getWrappedValue(get(instant), amount, iMin, iMax)); } /** * Set the specified amount of offset units to the specified time instant. * * @param instant the time instant in millis to update. * @param value value of units to set. * @return the updated time instant. * @throws IllegalArgumentException if value is too large or too small. */ public long set(long instant, int value) { FieldUtils.verifyValueBounds(this, value, iMin, iMax); return super.set(instant, value - iOffset); } public boolean isLeap(long instant) { return getWrappedField().isLeap(instant); } public int getLeapAmount(long instant) { return getWrappedField().getLeapAmount(instant); } public DurationField getLeapDurationField() { return getWrappedField().getLeapDurationField(); } /** * Get the minimum value for the field. * * @return the minimum value */ public int getMinimumValue() { return iMin; } /** * Get the maximum value for the field. * * @return the maximum value */ public int getMaximumValue() { return iMax; } public long roundFloor(long instant) { return getWrappedField().roundFloor(instant); } public long roundCeiling(long instant) { return getWrappedField().roundCeiling(instant); } public long roundHalfFloor(long instant) { return getWrappedField().roundHalfFloor(instant); } public long roundHalfCeiling(long instant) { return getWrappedField().roundHalfCeiling(instant); } public long roundHalfEven(long instant) { return getWrappedField().roundHalfEven(instant); } public long remainder(long instant) { return getWrappedField().remainder(instant); } /** * Returns the offset added to the field values. * * @return the offset */ public int getOffset() { return iOffset; } }